Network Security and Its Importance in Computer
Networks
Introduction
Network security is an intricate topic traditionally handled only by professionally trained and
experienced persons. Yet, as more and more individuals become connected through computer
networks, a rising number of people need to comprehend the fundamentals of security in a
networked environment.In the domain of networking, network security comprises of provisions
and guidelines established by the network administrator to curb and monitor illegal or
unauthorized access, misuse, alteration, or denial of the computer network and other network-
based resources (Stallings 2010).Network security comprises of a range of computer networks,
both private and public, that are employed in day-to-day tasks such as carrying out business
transactions and communication among firms, public and private institutions, enterprises, and
persons. Network security does just as its name goes, protects the network and manages all
processes being done on the network.
Objective
The objective of the paper is to expound on network security and its importance in computer
networks. Background information on computer networks will also be provided as well as risk
management, network threats, firewalls, and hardware and software devices that can be used
to improve the security of a computer network.
Introduction to Computer Networks
An elementary comprehension of computer networks is essential in order to understand the
codes of network security. A network is any set of interconnected lines, basing this definition
on the current topic, a computer network is basically a set of linked computers. Networks
enable users to share resources and information, and are classified base on a variety of protocols
(Network Security Threats 2011).For instance, a classification based on the connection manner
focuses on the hardware and software systems used to link the individual computer units, such
as optical fiber, wireless connection, or coaxial cable communication. Networks can also be
categorized on scale, this gives Local Area Network (LAN), wide area Network, virtual Private
Network (VPN), among others (Stallings 2010).
Networks are made up of ‘nodes’, which are the individual computers in the network, and at
least one server and/or ‘host’ computers. The nodes are linked together by communication
systems, which may be private, such as that within an institution, or can be accessed by the
public, such as the internet. Several private networks also use the internet.
The moment a computer network is instituted, it immediately becomes vulnerable to network
security threats such as viruses and bugs that may affect the normal functioning of a computer.
Besides, the personal information such as usernames, passwords, credit card numbers and other
critical information may be at risk if the computer does not have adequate security measures.
There are very many threats in a network, some of which are so severe and can bring down a
large network consisting of thousands of computers.
Virus
In the domain of computer networks, a virus refers to a computer program that can replicate
itself, similar to the biological virus. A computer virus spreads from one computer to another
through an executable program that attaches itself on programs, files and folders.
It can spread through various means, for example, if one computer in a network becomes
‘infected’ with a virus, the rest of the computers in the network may become infected too if the
security features are inadequate.
It can also be spread through USB devices, CD, DVD, or portable had drives. A computer virus
may also spread by mailing a web address link to all addresses so that when a person clicks on
the message to go the website, the virus enters this new computer.
Certain viruses are less harmful, however, some are very harmful and can infect a computer in
the network through various ways (Simmonds 2004). A virus can corrupt the files or software
in a computer. Others may attack the computer hardware and bring the whole computer down.
Yet, some viruses may allow a person to have partial control of a computer, this allows for
unauthorized access to files and critical information stored in the computer’s hard drive.
Although the Windows platform is by far the most vulnerable, other operating systems can also
be attacked by viruses.
Network threats arising from viruses can be managed through various ways, however, the most
common technique is to install an antivirus software. UNIX-based systems such as Mac OS
and Linux are far more secure than Windows. Some anti-virus programs can scan file contents
and even zipped folders while some can also scan sent and received mails, a practice known as
‘on-access scanning’ (Simmonds 2004).Vulnerability to viruses can also be reduced by
carrying out data backups regularly on storage media that are not connected to the network or
computer. Security patches availed by software manufacturers can also assist in reducing
attacks by viruses. Secondary storage media must be scanned before opening in the host
computer.
Malware
Malware, short form of malicious software, is a program created to interrupt normal computer
operations or deny a user network or computer resources, gain partial control of the computer,
access files stored in the computer, gather network-based information such as passwords, and
other cruel or dishonest behavior (Curtin 1997).
Malware consists of a large number of malicious programs that includes viruses, Trojans
horses, worms, spyware, false adware, rootkits and other malicious programs. In 2009,
malware was listed as the second most dangerous threat to computer networks. Today, millions
of malware are created daily to exploit networks with weak security features.
Threats arising from malware can be removed using antivirus programs. Most antivirus have
an added feature of removing various malwares from the network of individual PCs. Besides,
anti-spyware software can be used to prevent spyware threats.
Denial-of-Service Attacks
A Denial-of-Service (DoS) attack is a practice aimed at making network resources unavailable
to some users. This vice entails the resolute efforts of a person or group of persons to prevent
an internet site or service functioning normally or bringing it down altogether. This network
threat is commonly committed against websites or services hosted on high profile internet
servers such as financial institutions and credit card payment services (Stallings 2010).
One mode of attack involves flooding a web server with requests in such a way that it cannot
respond to legitimate communication requests, or responds in a sluggish manner that virtually
renders it unusable. In general, DoS attacks are executed by either compelling the targeted
systems to reset, or using up its resources so that it is unable to offer the intended services.
DoS attacks are perhaps the most malicious and hardest to prevent or manage. They are the
most malicious due to the ease with which they can be launched and the difficulty of tracing
their origins, and it is difficult to deny the requests of the attacker without also blocking out
genuine requests for service.
DoS attacks can be prevented through various ways. The first technique is to use firewalls.
Firewalls have simple instructions of blocking or allowing certain IP addresses, or ports,
however, firewall are not very effective in some DoS attacks as they cannot distinguish
legitimate traffic from DoS traffic. Switches and routers can also be used to prevent these
attacks (Kizza 2006). Intrusion-prevention systems (IPS) have been successfully used to halt
DoS attacks that have signatures attached to them.
Unauthorized Access
This is a very wide terminology as it can refer to various types of attacks, however, the objective
of these attacks is to access some information that the computer or server is not supposed to
reveal. Unauthorized access to a computer or server can be achieved by using viruses, malware
and other malicious programs.
This form of threat can be waded off by using antivirus programs and security patches. Another
strategy used by intruders to access a computer on a network is a technique known as packet
sniffers. Packet sniffers can be used on a vulnerable network and they just ‘listen’ on the server
for words such as password or login in the packet stream, then sends the information thereafter
to the perpetrator.
This way, an intruder is able to obtain usernames, passwords, credit card information and other
critical information from unsuspecting users (Bragg et al 2010). This type of threat can be
prevented by using clear-text passwords, besides, data encryption can help divert such attacks.
When using a wireless network, it is advisable that one should use a long or complicated
password, also, it is advisable that the strongest security supported by the wireless connection
hardware should be used, such as encryption tools. Passwords can also be changed regularly.
General Methods for Preventing Network Attacks and Reducing Vulnerability on
Networks
The most commonly used technique for reducing network threats is the installation of antivirus
programs. These programs must be regularly updated and security patches and updates
installed. Improving the security of the network infrastructure can also involve switching on
features that enhance network security on switches, routers, and other hardware (Fadia 2006).
These security features ensure a secure connection, enhance perimeter security, prevents
intrusion, protects identity services, and general security management. Fixing intrusion
detection systems and firewalls offers protection for most areas of the network and allows for
a safe connection. Working on a virtual private network (VPN) can also enhance security. VPNs
provide network access control and encryption services.
Network security can also be improved by undertaking regular network security audits. A
network security audit simply means that an expert comes and examines the security of the
network, he also checks for loopholes that may be used attack the system and fixes them.
The audit can go beyond an inspection of the computers in the network and may comprise a
site assessment of the physical security of the organization. A network security audit fixes an
organization security flaws in the network and makes it difficult for perpetrators to attack the
network (Network Security Threats 2011).
Since network threats come in a variety of forms and cannot be totally eliminated, it is advisable
that secure updated data backups should be kept on systems that are detached from the network.
None of these strategies will singly eliminate the threats arising from a network connection,
but when they are used together, they can be exceedingly effectual at keeping a network safe.
Besides, well –thought-out organizational policies can be effective at preventing unauthorized
access to critical and parts of the network.
Introduction to Computer Networks
An elementary comprehension of computer networks is essential in order to understand the
codes of network security. A network is any set of interconnected lines, basing this definition
on the current topic, a computer network is basically a set of linked computers. Networks
enable users to share resources and information, and are classified base on a variety of protocols
(Network Security Threats 2011).For instance, a classification based on the connection manner
focuses on the hardware and software systems used to link the individual computer units, such
as optical fiber, wireless connection, or coaxial cable communication. Networks can also be
categorized on scale, this gives Local Area Network (LAN), wide area Network, virtual Private
Network (VPN), among others (Stallings 2010).
Networks are made up of ‘nodes’, which are the individual computers in the network, and at
least one server and/or ‘host’ computers. The nodes are linked together by communication
systems, which may be private, such as that within an institution, or can be accessed by the
public, such as the internet. Several private networks also use the internet.
The moment a computer network is instituted, it immediately becomes vulnerable to network
security threats such as viruses and bugs that may affect the normal functioning of a computer.
Besides, the personal information such as usernames, passwords, credit card numbers and other
critical information may be at risk if the computer does not have adequate security measures.
There are very many threats in a network, some of which are so severe and can bring down a
large network consisting of thousands of computers.
Virus
In the domain of computer networks, a virus refers to a computer program that can replicate
itself, similar to the biological virus. A computer virus spreads from one computer to another
through an executable program that attaches itself on programs, files and folders.
It can spread through various means, for example, if one computer in a network becomes
‘infected’ with a virus, the rest of the computers in the network may become infected too if the
security features are inadequate.
It can also be spread through USB devices, CD, DVD, or portable had drives. A computer virus
may also spread by mailing a web address link to all addresses so that when a person clicks on
the message to go the website, the virus enters this new computer.
Certain viruses are less harmful, however, some are very harmful and can infect a computer in
the network through various ways (Simmonds 2004). A virus can corrupt the files or software
in a computer. Others may attack the computer hardware and bring the whole computer down.
Yet, some viruses may allow a person to have partial control of a computer, this allows for
unauthorized access to files and critical information stored in the computer’s hard drive.
Although the Windows platform is by far the most vulnerable, other operating systems can also
be attacked by viruses.
Network threats arising from viruses can be managed through various ways, however, the most
common technique is to install an antivirus software. UNIX-based systems such as Mac OS
and Linux are far more secure than Windows. Some anti-virus programs can scan file contents
and even zipped folders while some can also scan sent and received mails, a practice known as
‘on-access scanning’ (Simmonds 2004).Vulnerability to viruses can also be reduced by
carrying out data backups regularly on storage media that are not connected to the network or
computer. Security patches availed by software manufacturers can also assist in reducing
attacks by viruses. Secondary storage media must be scanned before opening in the host
computer.
Malware
Malware, short form of malicious software, is a program created to interrupt normal computer
operations or deny a user network or computer resources, gain partial control of the computer,
access files stored in the computer, gather network-based information such as passwords, and
other cruel or dishonest behavior (Curtin 1997).
Malware consists of a large number of malicious programs that includes viruses, Trojans
horses, worms, spyware, false adware, rootkits and other malicious programs. In 2009,
malware was listed as the second most dangerous threat to computer networks. Today, millions
of malware are created daily to exploit networks with weak security features.
Threats arising from malware can be removed using antivirus programs. Most antivirus have
an added feature of removing various malwares from the network of individual PCs. Besides,
anti-spyware software can be used to prevent spyware threats.
Denial-of-Service Attacks
A Denial-of-Service (DoS) attack is a practice aimed at making network resources unavailable
to some users. This vice entails the resolute efforts of a person or group of persons to prevent
an internet site or service functioning normally or bringing it down altogether. This network
threat is commonly committed against websites or services hosted on high profile internet
servers such as financial institutions and credit card payment services (Stallings 2010).
One mode of attack involves flooding a web server with requests in such a way that it cannot
respond to legitimate communication requests, or responds in a sluggish manner that virtually
renders it unusable. In general, DoS attacks are executed by either compelling the targeted
systems to reset, or using up its resources so that it is unable to offer the intended services.
DoS attacks are perhaps the most malicious and hardest to prevent or manage. They are the
most malicious due to the ease with which they can be launched and the difficulty of tracing
their origins, and it is difficult to deny the requests of the attacker without also blocking out
genuine requests for service.
DoS attacks can be prevented through various ways. The first technique is to use firewalls.
Firewalls have simple instructions of blocking or allowing certain IP addresses, or ports,
however, firewall are not very effective in some DoS attacks as they cannot distinguish
legitimate traffic from DoS traffic. Switches and routers can also be used to prevent these
attacks (Kizza 2006). Intrusion-prevention systems (IPS) have been successfully used to halt
DoS attacks that have signatures attached to them.
Unauthorized Access
This is a very wide terminology as it can refer to various types of attacks, however, the objective
of these attacks is to access some information that the computer or server is not supposed to
reveal. Unauthorized access to a computer or server can be achieved by using viruses, malware
and other malicious programs.
This form of threat can be waded off by using antivirus programs and security patches. Another
strategy used by intruders to access a computer on a network is a technique known as packet
sniffers. Packet sniffers can be used on a vulnerable network and they just ‘listen’ on the server
for words such as password or login in the packet stream, then sends the information thereafter
to the perpetrator.
This way, an intruder is able to obtain usernames, passwords, credit card information and other
critical information from unsuspecting users (Bragg et al 2010). This type of threat can be
prevented by using clear-text passwords, besides, data encryption can help divert such attacks.
When using a wireless network, it is advisable that one should use a long or complicated
password, also, it is advisable that the strongest security supported by the wireless connection
hardware should be used, such as encryption tools. Passwords can also be changed regularly.
General Methods for Preventing Network Attacks and Reducing Vulnerability on
Networks
The most commonly used technique for reducing network threats is the installation of antivirus
programs. These programs must be regularly updated and security patches and updates
installed. Improving the security of the network infrastructure can also involve switching on
features that enhance network security on switches, routers, and other hardware (Fadia 2006).
These security features ensure a secure connection, enhance perimeter security, prevents
intrusion, protects identity services, and general security management. Fixing intrusion
detection systems and firewalls offers protection for most areas of the network and allows for
a safe connection. Working on a virtual private network (VPN) can also enhance security. VPNs
provide network access control and encryption services.
Network security can also be improved by undertaking regular network security audits. A
network security audit simply means that an expert comes and examines the security of the
network, he also checks for loopholes that may be used attack the system and fixes them.
The audit can go beyond an inspection of the computers in the network and may comprise a
site assessment of the physical security of the organization. A network security audit fixes an
organization security flaws in the network and makes it difficult for perpetrators to attack the
network (Network Security Threats 2011).
Since network threats come in a variety of forms and cannot be totally eliminated, it is advisable
that secure updated data backups should be kept on systems that are detached from the network.
None of these strategies will singly eliminate the threats arising from a network connection,
but when they are used together, they can be exceedingly effectual at keeping a network safe.
Besides, well –thought-out organizational policies can be effective at preventing unauthorized
access to critical and parts of the network.
Introduction to Computer Networks
An elementary comprehension of computer networks is essential in order to understand the
codes of network security. A network is any set of interconnected lines, basing this definition
on the current topic, a computer network is basically a set of linked computers. Networks
enable users to share resources and information, and are classified base on a variety of protocols
(Network Security Threats 2011).For instance, a classification based on the connection manner
focuses on the hardware and software systems used to link the individual computer units, such
as optical fiber, wireless connection, or coaxial cable communication. Networks can also be
categorized on scale, this gives Local Area Network (LAN), wide area Network, virtual Private
Network (VPN), among others (Stallings 2010).
Networks are made up of ‘nodes’, which are the individual computers in the network, and at
least one server and/or ‘host’ computers. The nodes are linked together by communication
systems, which may be private, such as that within an institution, or can be accessed by the
public, such as the internet. Several private networks also use the internet.
The moment a computer network is instituted, it immediately becomes vulnerable to network
security threats such as viruses and bugs that may affect the normal functioning of a computer.
Besides, the personal information such as usernames, passwords, credit card numbers and other
critical information may be at risk if the computer does not have adequate security measures.
There are very many threats in a network, some of which are so severe and can bring down a
large network consisting of thousands of computers.
Virus
In the domain of computer networks, a virus refers to a computer program that can replicate
itself, similar to the biological virus. A computer virus spreads from one computer to another
through an executable program that attaches itself on programs, files and folders.
It can spread through various means, for example, if one computer in a network becomes
‘infected’ with a virus, the rest of the computers in the network may become infected too if the
security features are inadequate.
It can also be spread through USB devices, CD, DVD, or portable had drives. A computer virus
may also spread by mailing a web address link to all addresses so that when a person clicks on
the message to go the website, the virus enters this new computer.
Certain viruses are less harmful, however, some are very harmful and can infect a computer in
the network through various ways (Simmonds 2004). A virus can corrupt the files or software
in a computer. Others may attack the computer hardware and bring the whole computer down.
Yet, some viruses may allow a person to have partial control of a computer, this allows for
unauthorized access to files and critical information stored in the computer’s hard drive.
Although the Windows platform is by far the most vulnerable, other operating systems can also
be attacked by viruses.
Network threats arising from viruses can be managed through various ways, however, the most
common technique is to install an antivirus software. UNIX-based systems such as Mac OS
and Linux are far more secure than Windows. Some anti-virus programs can scan file contents
and even zipped folders while some can also scan sent and received mails, a practice known as
‘on-access scanning’ (Simmonds 2004).Vulnerability to viruses can also be reduced by
carrying out data backups regularly on storage media that are not connected to the network or
computer. Security patches availed by software manufacturers can also assist in reducing
attacks by viruses. Secondary storage media must be scanned before opening in the host
computer.
Malware
Malware, short form of malicious software, is a program created to interrupt normal computer
operations or deny a user network or computer resources, gain partial control of the computer,
access files stored in the computer, gather network-based information such as passwords, and
other cruel or dishonest behavior (Curtin 1997).
Malware consists of a large number of malicious programs that includes viruses, Trojans
horses, worms, spyware, false adware, rootkits and other malicious programs. In 2009,
malware was listed as the second most dangerous threat to computer networks. Today, millions
of malware are created daily to exploit networks with weak security features.
Threats arising from malware can be removed using antivirus programs. Most antivirus have
an added feature of removing various malwares from the network of individual PCs. Besides,
anti-spyware software can be used to prevent spyware threats.
Denial-of-Service Attacks
A Denial-of-Service (DoS) attack is a practice aimed at making network resources unavailable
to some users. This vice entails the resolute efforts of a person or group of persons to prevent
an internet site or service functioning normally or bringing it down altogether. This network
threat is commonly committed against websites or services hosted on high profile internet
servers such as financial institutions and credit card payment services (Stallings 2010).
One mode of attack involves flooding a web server with requests in such a way that it cannot
respond to legitimate communication requests, or responds in a sluggish manner that virtually
renders it unusable. In general, DoS attacks are executed by either compelling the targeted
systems to reset, or using up its resources so that it is unable to offer the intended services.
DoS attacks are perhaps the most malicious and hardest to prevent or manage. They are the
most malicious due to the ease with which they can be launched and the difficulty of tracing
their origins, and it is difficult to deny the requests of the attacker without also blocking out
genuine requests for service.
DoS attacks can be prevented through various ways. The first technique is to use firewalls.
Firewalls have simple instructions of blocking or allowing certain IP addresses, or ports,
however, firewall are not very effective in some DoS attacks as they cannot distinguish
legitimate traffic from DoS traffic. Switches and routers can also be used to prevent these
attacks (Kizza 2006). Intrusion-prevention systems (IPS) have been successfully used to halt
DoS attacks that have signatures attached to them.
Unauthorized Access
This is a very wide terminology as it can refer to various types of attacks, however, the objective
of these attacks is to access some information that the computer or server is not supposed to
reveal. Unauthorized access to a computer or server can be achieved by using viruses, malware
and other malicious programs.
This form of threat can be waded off by using antivirus programs and security patches. Another
strategy used by intruders to access a computer on a network is a technique known as packet
sniffers. Packet sniffers can be used on a vulnerable network and they just ‘listen’ on the server
for words such as password or login in the packet stream, then sends the information thereafter
to the perpetrator.
This way, an intruder is able to obtain usernames, passwords, credit card information and other
critical information from unsuspecting users (Bragg et al 2010). This type of threat can be
prevented by using clear-text passwords, besides, data encryption can help divert such attacks.
When using a wireless network, it is advisable that one should use a long or complicated
password, also, it is advisable that the strongest security supported by the wireless connection
hardware should be used, such as encryption tools. Passwords can also be changed regularly.
General Methods for Preventing Network Attacks and Reducing Vulnerability on
Networks
The most commonly used technique for reducing network threats is the installation of antivirus
programs. These programs must be regularly updated and security patches and updates
installed. Improving the security of the network infrastructure can also involve switching on
features that enhance network security on switches, routers, and other hardware (Fadia 2006).
These security features ensure a secure connection, enhance perimeter security, prevents
intrusion, protects identity services, and general security management. Fixing intrusion
detection systems and firewalls offers protection for most areas of the network and allows for
a safe connection. Working on a virtual private network (VPN) can also enhance security. VPNs
provide network access control and encryption services.
Network security can also be improved by undertaking regular network security audits. A
network security audit simply means that an expert comes and examines the security of the
network, he also checks for loopholes that may be used attack the system and fixes them.
The audit can go beyond an inspection of the computers in the network and may comprise a
site assessment of the physical security of the organization. A network security audit fixes an
organization security flaws in the network and makes it difficult for perpetrators to attack the
network (Network Security Threats 2011).
Since network threats come in a variety of forms and cannot be totally eliminated, it is advisable
that secure updated data backups should be kept on systems that are detached from the network.
None of these strategies will singly eliminate the threats arising from a network connection,
but when they are used together, they can be exceedingly effectual at keeping a network safe.
Besides, well –thought-out organizational policies can be effective at preventing unauthorized
access to critical and parts of the network.
Introduction to Computer Networks
An elementary comprehension of computer networks is essential in order to understand the
codes of network security. A network is any set of interconnected lines, basing this definition
on the current topic, a computer network is basically a set of linked computers. Networks
enable users to share resources and information, and are classified base on a variety of protocols
(Network Security Threats 2011).For instance, a classification based on the connection manner
focuses on the hardware and software systems used to link the individual computer units, such
as optical fiber, wireless connection, or coaxial cable communication. Networks can also be
categorized on scale, this gives Local Area Network (LAN), wide area Network, virtual Private
Network (VPN), among others (Stallings 2010).
Networks are made up of ‘nodes’, which are the individual computers in the network, and at
least one server and/or ‘host’ computers. The nodes are linked together by communication
systems, which may be private, such as that within an institution, or can be accessed by the
public, such as the internet. Several private networks also use the internet.
The moment a computer network is instituted, it immediately becomes vulnerable to network
security threats such as viruses and bugs that may affect the normal functioning of a computer.
Besides, the personal information such as usernames, passwords, credit card numbers and other
critical information may be at risk if the computer does not have adequate security measures.
There are very many threats in a network, some of which are so severe and can bring down a
large network consisting of thousands of computers.
Virus
In the domain of computer networks, a virus refers to a computer program that can replicate
itself, similar to the biological virus. A computer virus spreads from one computer to another
through an executable program that attaches itself on programs, files and folders.
It can spread through various means, for example, if one computer in a network becomes
‘infected’ with a virus, the rest of the computers in the network may become infected too if the
security features are inadequate.
It can also be spread through USB devices, CD, DVD, or portable had drives. A computer virus
may also spread by mailing a web address link to all addresses so that when a person clicks on
the message to go the website, the virus enters this new computer.
Certain viruses are less harmful, however, some are very harmful and can infect a computer in
the network through various ways (Simmonds 2004). A virus can corrupt the files or software
in a computer. Others may attack the computer hardware and bring the whole computer down.
Yet, some viruses may allow a person to have partial control of a computer, this allows for
unauthorized access to files and critical information stored in the computer’s hard drive.
Although the Windows platform is by far the most vulnerable, other operating systems can also
be attacked by viruses.
Network threats arising from viruses can be managed through various ways, however, the most
common technique is to install an antivirus software. UNIX-based systems such as Mac OS
and Linux are far more secure than Windows. Some anti-virus programs can scan file contents
and even zipped folders while some can also scan sent and received mails, a practice known as
‘on-access scanning’ (Simmonds 2004).Vulnerability to viruses can also be reduced by
carrying out data backups regularly on storage media that are not connected to the network or
computer. Security patches availed by software manufacturers can also assist in reducing
attacks by viruses. Secondary storage media must be scanned before opening in the host
computer.
Malware
Malware, short form of malicious software, is a program created to interrupt normal computer
operations or deny a user network or computer resources, gain partial control of the computer,
access files stored in the computer, gather network-based information such as passwords, and
other cruel or dishonest behavior (Curtin 1997).
Malware consists of a large number of malicious programs that includes viruses, Trojans
horses, worms, spyware, false adware, rootkits and other malicious programs. In 2009,
malware was listed as the second most dangerous threat to computer networks. Today, millions
of malware are created daily to exploit networks with weak security features.
Threats arising from malware can be removed using antivirus programs. Most antivirus have
an added feature of removing various malwares from the network of individual PCs. Besides,
anti-spyware software can be used to prevent spyware threats.
Denial-of-Service Attacks
A Denial-of-Service (DoS) attack is a practice aimed at making network resources unavailable
to some users. This vice entails the resolute efforts of a person or group of persons to prevent
an internet site or service functioning normally or bringing it down altogether. This network
threat is commonly committed against websites or services hosted on high profile internet
servers such as financial institutions and credit card payment services (Stallings 2010).
One mode of attack involves flooding a web server with requests in such a way that it cannot
respond to legitimate communication requests, or responds in a sluggish manner that virtually
renders it unusable. In general, DoS attacks are executed by either compelling the targeted
systems to reset, or using up its resources so that it is unable to offer the intended services.
DoS attacks are perhaps the most malicious and hardest to prevent or manage. They are the
most malicious due to the ease with which they can be launched and the difficulty of tracing
their origins, and it is difficult to deny the requests of the attacker without also blocking out
genuine requests for service.
DoS attacks can be prevented through various ways. The first technique is to use firewalls.
Firewalls have simple instructions of blocking or allowing certain IP addresses, or ports,
however, firewall are not very effective in some DoS attacks as they cannot distinguish
legitimate traffic from DoS traffic. Switches and routers can also be used to prevent these
attacks (Kizza 2006). Intrusion-prevention systems (IPS) have been successfully used to halt
DoS attacks that have signatures attached to them.
Unauthorized Access
This is a very wide terminology as it can refer to various types of attacks, however, the objective
of these attacks is to access some information that the computer or server is not supposed to
reveal. Unauthorized access to a computer or server can be achieved by using viruses, malware
and other malicious programs.
This form of threat can be waded off by using antivirus programs and security patches. Another
strategy used by intruders to access a computer on a network is a technique known as packet
sniffers. Packet sniffers can be used on a vulnerable network and they just ‘listen’ on the server
for words such as password or login in the packet stream, then sends the information thereafter
to the perpetrator.
This way, an intruder is able to obtain usernames, passwords, credit card information and other
critical information from unsuspecting users (Bragg et al 2010). This type of threat can be
prevented by using clear-text passwords, besides, data encryption can help divert such attacks.
When using a wireless network, it is advisable that one should use a long or complicated
password, also, it is advisable that the strongest security supported by the wireless connection
hardware should be used, such as encryption tools. Passwords can also be changed regularly.
General Methods for Preventing Network Attacks and Reducing Vulnerability on
Networks
The most commonly used technique for reducing network threats is the installation of antivirus
programs. These programs must be regularly updated and security patches and updates
installed. Improving the security of the network infrastructure can also involve switching on
features that enhance network security on switches, routers, and other hardware (Fadia 2006).
These security features ensure a secure connection, enhance perimeter security, prevents
intrusion, protects identity services, and general security management. Fixing intrusion
detection systems and firewalls offers protection for most areas of the network and allows for
a safe connection. Working on a virtual private network (VPN) can also enhance security. VPNs
provide network access control and encryption services.
Network security can also be improved by undertaking regular network security audits. A
network security audit simply means that an expert comes and examines the security of the
network, he also checks for loopholes that may be used attack the system and fixes them.
The audit can go beyond an inspection of the computers in the network and may comprise a
site assessment of the physical security of the organization. A network security audit fixes an
organization security flaws in the network and makes it difficult for perpetrators to attack the
network (Network Security Threats 2011).
Since network threats come in a variety of forms and cannot be totally eliminated, it is advisable
that secure updated data backups should be kept on systems that are detached from the network.
None of these strategies will singly eliminate the threats arising from a network connection,
but when they are used together, they can be exceedingly effectual at keeping a network safe.
Besides, well –thought-out organizational policies can be effective at preventing unauthorized
access to critical and parts of the network.
Introduction to Computer Networks
An elementary comprehension of computer networks is essential in order to understand the
codes of network security. A network is any set of interconnected lines, basing this definition
on the current topic, a computer network is basically a set of linked computers. Networks
enable users to share resources and information, and are classified base on a variety of protocols
(Network Security Threats 2011).For instance, a classification based on the connection manner
focuses on the hardware and software systems used to link the individual computer units, such
as optical fiber, wireless connection, or coaxial cable communication. Networks can also be
categorized on scale, this gives Local Area Network (LAN), wide area Network, virtual Private
Network (VPN), among others (Stallings 2010).
Networks are made up of ‘nodes’, which are the individual computers in the network, and at
least one server and/or ‘host’ computers. The nodes are linked together by communication
systems, which may be private, such as that within an institution, or can be accessed by the
public, such as the internet. Several private networks also use the internet.
The moment a computer network is instituted, it immediately becomes vulnerable to network
security threats such as viruses and bugs that may affect the normal functioning of a computer.
Besides, the personal information such as usernames, passwords, credit card numbers and other
critical information may be at risk if the computer does not have adequate security measures.
There are very many threats in a network, some of which are so severe and can bring down a
large network consisting of thousands of computers.
Virus
In the domain of computer networks, a virus refers to a computer program that can replicate
itself, similar to the biological virus. A computer virus spreads from one computer to another
through an executable program that attaches itself on programs, files and folders.
It can spread through various means, for example, if one computer in a network becomes
‘infected’ with a virus, the rest of the computers in the network may become infected too if the
security features are inadequate.
It can also be spread through USB devices, CD, DVD, or portable had drives. A computer virus
may also spread by mailing a web address link to all addresses so that when a person clicks on
the message to go the website, the virus enters this new computer.
Certain viruses are less harmful, however, some are very harmful and can infect a computer in
the network through various ways (Simmonds 2004). A virus can corrupt the files or software
in a computer. Others may attack the computer hardware and bring the whole computer down.
Yet, some viruses may allow a person to have partial control of a computer, this allows for
unauthorized access to files and critical information stored in the computer’s hard drive.
Although the Windows platform is by far the most vulnerable, other operating systems can also
be attacked by viruses.
Network threats arising from viruses can be managed through various ways, however, the most
common technique is to install an antivirus software. UNIX-based systems such as Mac OS
and Linux are far more secure than Windows. Some anti-virus programs can scan file contents
and even zipped folders while some can also scan sent and received mails, a practice known as
‘on-access scanning’ (Simmonds 2004).Vulnerability to viruses can also be reduced by
carrying out data backups regularly on storage media that are not connected to the network or
computer. Security patches availed by software manufacturers can also assist in reducing
attacks by viruses. Secondary storage media must be scanned before opening in the host
computer.
Malware
Malware, short form of malicious software, is a program created to interrupt normal computer
operations or deny a user network or computer resources, gain partial control of the computer,
access files stored in the computer, gather network-based information such as passwords, and
other cruel or dishonest behavior (Curtin 1997).
Malware consists of a large number of malicious programs that includes viruses, Trojans
horses, worms, spyware, false adware, rootkits and other malicious programs. In 2009,
malware was listed as the second most dangerous threat to computer networks. Today, millions
of malware are created daily to exploit networks with weak security features.
Threats arising from malware can be removed using antivirus programs. Most antivirus have
an added feature of removing various malwares from the network of individual PCs. Besides,
anti-spyware software can be used to prevent spyware threats.
Denial-of-Service Attacks
A Denial-of-Service (DoS) attack is a practice aimed at making network resources unavailable
to some users. This vice entails the resolute efforts of a person or group of persons to prevent
an internet site or service functioning normally or bringing it down altogether. This network
threat is commonly committed against websites or services hosted on high profile internet
servers such as financial institutions and credit card payment services (Stallings 2010).
One mode of attack involves flooding a web server with requests in such a way that it cannot
respond to legitimate communication requests, or responds in a sluggish manner that virtually
renders it unusable. In general, DoS attacks are executed by either compelling the targeted
systems to reset, or using up its resources so that it is unable to offer the intended services.
DoS attacks are perhaps the most malicious and hardest to prevent or manage. They are the
most malicious due to the ease with which they can be launched and the difficulty of tracing
their origins, and it is difficult to deny the requests of the attacker without also blocking out
genuine requests for service.
DoS attacks can be prevented through various ways. The first technique is to use firewalls.
Firewalls have simple instructions of blocking or allowing certain IP addresses, or ports,
however, firewall are not very effective in some DoS attacks as they cannot distinguish
legitimate traffic from DoS traffic. Switches and routers can also be used to prevent these
attacks (Kizza 2006). Intrusion-prevention systems (IPS) have been successfully used to halt
DoS attacks that have signatures attached to them.
Unauthorized Access
This is a very wide terminology as it can refer to various types of attacks, however, the objective
of these attacks is to access some information that the computer or server is not supposed to
reveal. Unauthorized access to a computer or server can be achieved by using viruses, malware
and other malicious programs.
This form of threat can be waded off by using antivirus programs and security patches. Another
strategy used by intruders to access a computer on a network is a technique known as packet
sniffers. Packet sniffers can be used on a vulnerable network and they just ‘listen’ on the server
for words such as password or login in the packet stream, then sends the information thereafter
to the perpetrator.
This way, an intruder is able to obtain usernames, passwords, credit card information and other
critical information from unsuspecting users (Bragg et al 2010). This type of threat can be
prevented by using clear-text passwords, besides, data encryption can help divert such attacks.
When using a wireless network, it is advisable that one should use a long or complicated
password, also, it is advisable that the strongest security supported by the wireless connection
hardware should be used, such as encryption tools. Passwords can also be changed regularly.
General Methods for Preventing Network Attacks and Reducing Vulnerability on
Networks
The most commonly used technique for reducing network threats is the installation of antivirus
programs. These programs must be regularly updated and security patches and updates
installed. Improving the security of the network infrastructure can also involve switching on
features that enhance network security on switches, routers, and other hardware (Fadia 2006).
These security features ensure a secure connection, enhance perimeter security, prevents
intrusion, protects identity services, and general security management. Fixing intrusion
detection systems and firewalls offers protection for most areas of the network and allows for
a safe connection. Working on a virtual private network (VPN) can also enhance security. VPNs
provide network access control and encryption services.
Network security can also be improved by undertaking regular network security audits. A
network security audit simply means that an expert comes and examines the security of the
network, he also checks for loopholes that may be used attack the system and fixes them.
The audit can go beyond an inspection of the computers in the network and may comprise a
site assessment of the physical security of the organization. A network security audit fixes an
organization security flaws in the network and makes it difficult for perpetrators to attack the
network (Network Security Threats 2011).
Since network threats come in a variety of forms and cannot be totally eliminated, it is advisable
that secure updated data backups should be kept on systems that are detached from the network.
None of these strategies will singly eliminate the threats arising from a network connection,
but when they are used together, they can be exceedingly effectual at keeping a network safe.
Besides, well –thought-out organizational policies can be effective at preventing unauthorized
access to critical and parts of the network.
Introduction to Computer Networks
An elementary comprehension of computer networks is essential in order to understand the
codes of network security. A network is any set of interconnected lines, basing this definition
on the current topic, a computer network is basically a set of linked computers. Networks
enable users to share resources and information, and are classified base on a variety of protocols
(Network Security Threats 2011).For instance, a classification based on the connection manner
focuses on the hardware and software systems used to link the individual computer units, such
as optical fiber, wireless connection, or coaxial cable communication. Networks can also be
categorized on scale, this gives Local Area Network (LAN), wide area Network, virtual Private
Network (VPN), among others (Stallings 2010).
Networks are made up of ‘nodes’, which are the individual computers in the network, and at
least one server and/or ‘host’ computers. The nodes are linked together by communication
systems, which may be private, such as that within an institution, or can be accessed by the
public, such as the internet. Several private networks also use the internet.
The moment a computer network is instituted, it immediately becomes vulnerable to network
security threats such as viruses and bugs that may affect the normal functioning of a computer.
Besides, the personal information such as usernames, passwords, credit card numbers and other
critical information may be at risk if the computer does not have adequate security measures.
There are very many threats in a network, some of which are so severe and can bring down a
large network consisting of thousands of computers.
Virus
In the domain of computer networks, a virus refers to a computer program that can replicate
itself, similar to the biological virus. A computer virus spreads from one computer to another
through an executable program that attaches itself on programs, files and folders.
It can spread through various means, for example, if one computer in a network becomes
‘infected’ with a virus, the rest of the computers in the network may become infected too if the
security features are inadequate.
It can also be spread through USB devices, CD, DVD, or portable had drives. A computer virus
may also spread by mailing a web address link to all addresses so that when a person clicks on
the message to go the website, the virus enters this new computer.
Certain viruses are less harmful, however, some are very harmful and can infect a computer in
the network through various ways (Simmonds 2004). A virus can corrupt the files or software
in a computer. Others may attack the computer hardware and bring the whole computer down.
Yet, some viruses may allow a person to have partial control of a computer, this allows for
unauthorized access to files and critical information stored in the computer’s hard drive.
Although the Windows platform is by far the most vulnerable, other operating systems can also
be attacked by viruses.
Network threats arising from viruses can be managed through various ways, however, the most
common technique is to install an antivirus software. UNIX-based systems such as Mac OS
and Linux are far more secure than Windows. Some anti-virus programs can scan file contents
and even zipped folders while some can also scan sent and received mails, a practice known as
‘on-access scanning’ (Simmonds 2004).Vulnerability to viruses can also be reduced by
carrying out data backups regularly on storage media that are not connected to the network or
computer. Security patches availed by software manufacturers can also assist in reducing
attacks by viruses. Secondary storage media must be scanned before opening in the host
computer.
Malware
Malware, short form of malicious software, is a program created to interrupt normal computer
operations or deny a user network or computer resources, gain partial control of the computer,
access files stored in the computer, gather network-based information such as passwords, and
other cruel or dishonest behavior (Curtin 1997).
Malware consists of a large number of malicious programs that includes viruses, Trojans
horses, worms, spyware, false adware, rootkits and other malicious programs. In 2009,
malware was listed as the second most dangerous threat to computer networks. Today, millions
of malware are created daily to exploit networks with weak security features.
Threats arising from malware can be removed using antivirus programs. Most antivirus have
an added feature of removing various malwares from the network of individual PCs. Besides,
anti-spyware software can be used to prevent spyware threats.
Denial-of-Service Attacks
A Denial-of-Service (DoS) attack is a practice aimed at making network resources unavailable
to some users. This vice entails the resolute efforts of a person or group of persons to prevent
an internet site or service functioning normally or bringing it down altogether. This network
threat is commonly committed against websites or services hosted on high profile internet
servers such as financial institutions and credit card payment services (Stallings 2010).
One mode of attack involves flooding a web server with requests in such a way that it cannot
respond to legitimate communication requests, or responds in a sluggish manner that virtually
renders it unusable. In general, DoS attacks are executed by either compelling the targeted
systems to reset, or using up its resources so that it is unable to offer the intended services.
DoS attacks are perhaps the most malicious and hardest to prevent or manage. They are the
most malicious due to the ease with which they can be launched and the difficulty of tracing
their origins, and it is difficult to deny the requests of the attacker without also blocking out
genuine requests for service.
DoS attacks can be prevented through various ways. The first technique is to use firewalls.
Firewalls have simple instructions of blocking or allowing certain IP addresses, or ports,
however, firewall are not very effective in some DoS attacks as they cannot distinguish
legitimate traffic from DoS traffic. Switches and routers can also be used to prevent these
attacks (Kizza 2006). Intrusion-prevention systems (IPS) have been successfully used to halt
DoS attacks that have signatures attached to them.
Unauthorized Access
This is a very wide terminology as it can refer to various types of attacks, however, the objective
of these attacks is to access some information that the computer or server is not supposed to
reveal. Unauthorized access to a computer or server can be achieved by using viruses, malware
and other malicious programs.
This form of threat can be waded off by using antivirus programs and security patches. Another
strategy used by intruders to access a computer on a network is a technique known as packet
sniffers. Packet sniffers can be used on a vulnerable network and they just ‘listen’ on the server
for words such as password or login in the packet stream, then sends the information thereafter
to the perpetrator.
This way, an intruder is able to obtain usernames, passwords, credit card information and other
critical information from unsuspecting users (Bragg et al 2010). This type of threat can be
prevented by using clear-text passwords, besides, data encryption can help divert such attacks.
When using a wireless network, it is advisable that one should use a long or complicated
password, also, it is advisable that the strongest security supported by the wireless connection
hardware should be used, such as encryption tools. Passwords can also be changed regularly.
General Methods for Preventing Network Attacks and Reducing Vulnerability on
Networks
The most commonly used technique for reducing network threats is the installation of antivirus
programs. These programs must be regularly updated and security patches and updates
installed. Improving the security of the network infrastructure can also involve switching on
features that enhance network security on switches, routers, and other hardware (Fadia 2006).
These security features ensure a secure connection, enhance perimeter security, prevents
intrusion, protects identity services, and general security management. Fixing intrusion
detection systems and firewalls offers protection for most areas of the network and allows for
a safe connection. Working on a virtual private network (VPN) can also enhance security. VPNs
provide network access control and encryption services.
Network security can also be improved by undertaking regular network security audits. A
network security audit simply means that an expert comes and examines the security of the
network, he also checks for loopholes that may be used attack the system and fixes them.
The audit can go beyond an inspection of the computers in the network and may comprise a
site assessment of the physical security of the organization. A network security audit fixes an
organization security flaws in the network and makes it difficult for perpetrators to attack the
network (Network Security Threats 2011).
Since network threats come in a variety of forms and cannot be totally eliminated, it is advisable
that secure updated data backups should be kept on systems that are detached from the network.
None of these strategies will singly eliminate the threats arising from a network connection,
but when they are used together, they can be exceedingly effectual at keeping a network safe.
Besides, well –thought-out organizational policies can be effective at preventing unauthorized
access to critical and parts of the network.
Introduction to Computer Networks
An elementary comprehension of computer networks is essential in order to understand the
codes of network security. A network is any set of interconnected lines, basing this definition
on the current topic, a computer network is basically a set of linked computers. Networks
enable users to share resources and information, and are classified base on a variety of protocols
(Network Security Threats 2011).For instance, a classification based on the connection manner
focuses on the hardware and software systems used to link the individual computer units, such
as optical fiber, wireless connection, or coaxial cable communication. Networks can also be
categorized on scale, this gives Local Area Network (LAN), wide area Network, virtual Private
Network (VPN), among others (Stallings 2010).
Networks are made up of ‘nodes’, which are the individual computers in the network, and at
least one server and/or ‘host’ computers. The nodes are linked together by communication
systems, which may be private, such as that within an institution, or can be accessed by the
public, such as the internet. Several private networks also use the internet.
The moment a computer network is instituted, it immediately becomes vulnerable to network
security threats such as viruses and bugs that may affect the normal functioning of a computer.
Besides, the personal information such as usernames, passwords, credit card numbers and other
critical information may be at risk if the computer does not have adequate security measures.
There are very many threats in a network, some of which are so severe and can bring down a
large network consisting of thousands of computers.
Virus
In the domain of computer networks, a virus refers to a computer program that can replicate
itself, similar to the biological virus. A computer virus spreads from one computer to another
through an executable program that attaches itself on programs, files and folders.
It can spread through various means, for example, if one computer in a network becomes
‘infected’ with a virus, the rest of the computers in the network may become infected too if the
security features are inadequate.
It can also be spread through USB devices, CD, DVD, or portable had drives. A computer virus
may also spread by mailing a web address link to all addresses so that when a person clicks on
the message to go the website, the virus enters this new computer.
Certain viruses are less harmful, however, some are very harmful and can infect a computer in
the network through various ways (Simmonds 2004). A virus can corrupt the files or software
in a computer. Others may attack the computer hardware and bring the whole computer down.
Yet, some viruses may allow a person to have partial control of a computer, this allows for
unauthorized access to files and critical information stored in the computer’s hard drive.
Although the Windows platform is by far the most vulnerable, other operating systems can also
be attacked by viruses.
Network threats arising from viruses can be managed through various ways, however, the most
common technique is to install an antivirus software. UNIX-based systems such as Mac OS
and Linux are far more secure than Windows. Some anti-virus programs can scan file contents
and even zipped folders while some can also scan sent and received mails, a practice known as
‘on-access scanning’ (Simmonds 2004).Vulnerability to viruses can also be reduced by
carrying out data backups regularly on storage media that are not connected to the network or
computer. Security patches availed by software manufacturers can also assist in reducing
attacks by viruses. Secondary storage media must be scanned before opening in the host
computer.
Malware
Malware, short form of malicious software, is a program created to interrupt normal computer
operations or deny a user network or computer resources, gain partial control of the computer,
access files stored in the computer, gather network-based information such as passwords, and
other cruel or dishonest behavior (Curtin 1997).
Malware consists of a large number of malicious programs that includes viruses, Trojans
horses, worms, spyware, false adware, rootkits and other malicious programs. In 2009,
malware was listed as the second most dangerous threat to computer networks. Today, millions
of malware are created daily to exploit networks with weak security features.
Threats arising from malware can be removed using antivirus programs. Most antivirus have
an added feature of removing various malwares from the network of individual PCs. Besides,
anti-spyware software can be used to prevent spyware threats.
Denial-of-Service Attacks
A Denial-of-Service (DoS) attack is a practice aimed at making network resources unavailable
to some users. This vice entails the resolute efforts of a person or group of persons to prevent
an internet site or service functioning normally or bringing it down altogether. This network
threat is commonly committed against websites or services hosted on high profile internet
servers such as financial institutions and credit card payment services (Stallings 2010).
One mode of attack involves flooding a web server with requests in such a way that it cannot
respond to legitimate communication requests, or responds in a sluggish manner that virtually
renders it unusable. In general, DoS attacks are executed by either compelling the targeted
systems to reset, or using up its resources so that it is unable to offer the intended services.
DoS attacks are perhaps the most malicious and hardest to prevent or manage. They are the
most malicious due to the ease with which they can be launched and the difficulty of tracing
their origins, and it is difficult to deny the requests of the attacker without also blocking out
genuine requests for service.
DoS attacks can be prevented through various ways. The first technique is to use firewalls.
Firewalls have simple instructions of blocking or allowing certain IP addresses, or ports,
however, firewall are not very effective in some DoS attacks as they cannot distinguish
legitimate traffic from DoS traffic. Switches and routers can also be used to prevent these
attacks (Kizza 2006). Intrusion-prevention systems (IPS) have been successfully used to halt
DoS attacks that have signatures attached to them.
Unauthorized Access
This is a very wide terminology as it can refer to various types of attacks, however, the objective
of these attacks is to access some information that the computer or server is not supposed to
reveal. Unauthorized access to a computer or server can be achieved by using viruses, malware
and other malicious programs.
This form of threat can be waded off by using antivirus programs and security patches. Another
strategy used by intruders to access a computer on a network is a technique known as packet
sniffers. Packet sniffers can be used on a vulnerable network and they just ‘listen’ on the server
for words such as password or login in the packet stream, then sends the information thereafter
to the perpetrator.
This way, an intruder is able to obtain usernames, passwords, credit card information and other
critical information from unsuspecting users (Bragg et al 2010). This type of threat can be
prevented by using clear-text passwords, besides, data encryption can help divert such attacks.
When using a wireless network, it is advisable that one should use a long or complicated
password, also, it is advisable that the strongest security supported by the wireless connection
hardware should be used, such as encryption tools. Passwords can also be changed regularly.
General Methods for Preventing Network Attacks and Reducing Vulnerability on
Networks
The most commonly used technique for reducing network threats is the installation of antivirus
programs. These programs must be regularly updated and security patches and updates
installed. Improving the security of the network infrastructure can also involve switching on
features that enhance network security on switches, routers, and other hardware (Fadia 2006).
These security features ensure a secure connection, enhance perimeter security, prevents
intrusion, protects identity services, and general security management. Fixing intrusion
detection systems and firewalls offers protection for most areas of the network and allows for
a safe connection. Working on a virtual private network (VPN) can also enhance security. VPNs
provide network access control and encryption services.
Network security can also be improved by undertaking regular network security audits. A
network security audit simply means that an expert comes and examines the security of the
network, he also checks for loopholes that may be used attack the system and fixes them.
The audit can go beyond an inspection of the computers in the network and may comprise a
site assessment of the physical security of the organization. A network security audit fixes an
organization security flaws in the network and makes it difficult for perpetrators to attack the
network (Network Security Threats 2011).
Since network threats come in a variety of forms and cannot be totally eliminated, it is advisable
that secure updated data backups should be kept on systems that are detached from the network.
None of these strategies will singly eliminate the threats arising from a network connection,
but when they are used together, they can be exceedingly effectual at keeping a network safe.
Besides, well –thought-out organizational policies can be effective at preventing unauthorized
access to critical and parts of the network.
Introduction to Computer Networks
An elementary comprehension of computer networks is essential in order to understand the
codes of network security. A network is any set of interconnected lines, basing this definition
on the current topic, a computer network is basically a set of linked computers. Networks
enable users to share resources and information, and are classified base on a variety of protocols
(Network Security Threats 2011).For instance, a classification based on the connection manner
focuses on the hardware and software systems used to link the individual computer units, such
as optical fiber, wireless connection, or coaxial cable communication. Networks can also be
categorized on scale, this gives Local Area Network (LAN), wide area Network, virtual Private
Network (VPN), among others (Stallings 2010).
Networks are made up of ‘nodes’, which are the individual computers in the network, and at
least one server and/or ‘host’ computers. The nodes are linked together by communication
systems, which may be private, such as that within an institution, or can be accessed by the
public, such as the internet. Several private networks also use the internet.
The moment a computer network is instituted, it immediately becomes vulnerable to network
security threats such as viruses and bugs that may affect the normal functioning of a computer.
Besides, the personal information such as usernames, passwords, credit card numbers and other
critical information may be at risk if the computer does not have adequate security measures.
There are very many threats in a network, some of which are so severe and can bring down a
large network consisting of thousands of computers.
Virus
In the domain of computer networks, a virus refers to a computer program that can replicate
itself, similar to the biological virus. A computer virus spreads from one computer to another
through an executable program that attaches itself on programs, files and folders.
It can spread through various means, for example, if one computer in a network becomes
‘infected’ with a virus, the rest of the computers in the network may become infected too if the
security features are inadequate.
It can also be spread through USB devices, CD, DVD, or portable had drives. A computer virus
may also spread by mailing a web address link to all addresses so that when a person clicks on
the message to go the website, the virus enters this new computer.
Certain viruses are less harmful, however, some are very harmful and can infect a computer in
the network through various ways (Simmonds 2004). A virus can corrupt the files or software
in a computer. Others may attack the computer hardware and bring the whole computer down.
Yet, some viruses may allow a person to have partial control of a computer, this allows for
unauthorized access to files and critical information stored in the computer’s hard drive.
Although the Windows platform is by far the most vulnerable, other operating systems can also
be attacked by viruses.
Network threats arising from viruses can be managed through various ways, however, the most
common technique is to install an antivirus software. UNIX-based systems such as Mac OS
and Linux are far more secure than Windows. Some anti-virus programs can scan file contents
and even zipped folders while some can also scan sent and received mails, a practice known as
‘on-access scanning’ (Simmonds 2004).Vulnerability to viruses can also be reduced by
carrying out data backups regularly on storage media that are not connected to the network or
computer. Security patches availed by software manufacturers can also assist in reducing
attacks by viruses. Secondary storage media must be scanned before opening in the host
computer.
Malware
Malware, short form of malicious software, is a program created to interrupt normal computer
operations or deny a user network or computer resources, gain partial control of the computer,
access files stored in the computer, gather network-based information such as passwords, and
other cruel or dishonest behavior (Curtin 1997).
Malware consists of a large number of malicious programs that includes viruses, Trojans
horses, worms, spyware, false adware, rootkits and other malicious programs. In 2009,
malware was listed as the second most dangerous threat to computer networks. Today, millions
of malware are created daily to exploit networks with weak security features.
Threats arising from malware can be removed using antivirus programs. Most antivirus have
an added feature of removing various malwares from the network of individual PCs. Besides,
anti-spyware software can be used to prevent spyware threats.
Denial-of-Service Attacks
A Denial-of-Service (DoS) attack is a practice aimed at making network resources unavailable
to some users. This vice entails the resolute efforts of a person or group of persons to prevent
an internet site or service functioning normally or bringing it down altogether. This network
threat is commonly committed against websites or services hosted on high profile internet
servers such as financial institutions and credit card payment services (Stallings 2010).
One mode of attack involves flooding a web server with requests in such a way that it cannot
respond to legitimate communication requests, or responds in a sluggish manner that virtually
renders it unusable. In general, DoS attacks are executed by either compelling the targeted
systems to reset, or using up its resources so that it is unable to offer the intended services.
DoS attacks are perhaps the most malicious and hardest to prevent or manage. They are the
most malicious due to the ease with which they can be launched and the difficulty of tracing
their origins, and it is difficult to deny the requests of the attacker without also blocking out
genuine requests for service.
DoS attacks can be prevented through various ways. The first technique is to use firewalls.
Firewalls have simple instructions of blocking or allowing certain IP addresses, or ports,
however, firewall are not very effective in some DoS attacks as they cannot distinguish
legitimate traffic from DoS traffic. Switches and routers can also be used to prevent these
attacks (Kizza 2006). Intrusion-prevention systems (IPS) have been successfully used to halt
DoS attacks that have signatures attached to them.
Unauthorized Access
This is a very wide terminology as it can refer to various types of attacks, however, the objective
of these attacks is to access some information that the computer or server is not supposed to
reveal. Unauthorized access to a computer or server can be achieved by using viruses, malware
and other malicious programs.
This form of threat can be waded off by using antivirus programs and security patches. Another
strategy used by intruders to access a computer on a network is a technique known as packet
sniffers. Packet sniffers can be used on a vulnerable network and they just ‘listen’ on the server
for words such as password or login in the packet stream, then sends the information thereafter
to the perpetrator.
This way, an intruder is able to obtain usernames, passwords, credit card information and other
critical information from unsuspecting users (Bragg et al 2010). This type of threat can be
prevented by using clear-text passwords, besides, data encryption can help divert such attacks.
When using a wireless network, it is advisable that one should use a long or complicated
password, also, it is advisable that the strongest security supported by the wireless connection
hardware should be used, such as encryption tools. Passwords can also be changed regularly.
General Methods for Preventing Network Attacks and Reducing Vulnerability on
Networks
The most commonly used technique for reducing network threats is the installation of antivirus
programs. These programs must be regularly updated and security patches and updates
installed. Improving the security of the network infrastructure can also involve switching on
features that enhance network security on switches, routers, and other hardware (Fadia 2006).
These security features ensure a secure connection, enhance perimeter security, prevents
intrusion, protects identity services, and general security management. Fixing intrusion
detection systems and firewalls offers protection for most areas of the network and allows for
a safe connection. Working on a virtual private network (VPN) can also enhance security. VPNs
provide network access control and encryption services.
Network security can also be improved by undertaking regular network security audits. A
network security audit simply means that an expert comes and examines the security of the
network, he also checks for loopholes that may be used attack the system and fixes them.
The audit can go beyond an inspection of the computers in the network and may comprise a
site assessment of the physical security of the organization. A network security audit fixes an
organization security flaws in the network and makes it difficult for perpetrators to attack the
network (Network Security Threats 2011).
Since network threats come in a variety of forms and cannot be totally eliminated, it is advisable
that secure updated data backups should be kept on systems that are detached from the network.
None of these strategies will singly eliminate the threats arising from a network connection,
but when they are used together, they can be exceedingly effectual at keeping a network safe.
Besides, well –thought-out organizational policies can be effective at preventing unauthorized
access to critical and parts of the network.
Introduction to Computer Networks
An elementary comprehension of computer networks is essential in order to understand the
codes of network security. A network is any set of interconnected lines, basing this definition
on the current topic, a computer network is basically a set of linked computers. Networks
enable users to share resources and information, and are classified base on a variety of protocols
(Network Security Threats 2011).For instance, a classification based on the connection manner
focuses on the hardware and software systems used to link the individual computer units, such
as optical fiber, wireless connection, or coaxial cable communication. Networks can also be
categorized on scale, this gives Local Area Network (LAN), wide area Network, virtual Private
Network (VPN), among others (Stallings 2010).
Networks are made up of ‘nodes’, which are the individual computers in the network, and at
least one server and/or ‘host’ computers. The nodes are linked together by communication
systems, which may be private, such as that within an institution, or can be accessed by the
public, such as the internet. Several private networks also use the internet.
The moment a computer network is instituted, it immediately becomes vulnerable to network
security threats such as viruses and bugs that may affect the normal functioning of a computer.
Besides, the personal information such as usernames, passwords, credit card numbers and other
critical information may be at risk if the computer does not have adequate security measures.
There are very many threats in a network, some of which are so severe and can bring down a
large network consisting of thousands of computers.
Virus
In the domain of computer networks, a virus refers to a computer program that can replicate
itself, similar to the biological virus. A computer virus spreads from one computer to another
through an executable program that attaches itself on programs, files and folders.
It can spread through various means, for example, if one computer in a network becomes
‘infected’ with a virus, the rest of the computers in the network may become infected too if the
security features are inadequate.
It can also be spread through USB devices, CD, DVD, or portable had drives. A computer virus
may also spread by mailing a web address link to all addresses so that when a person clicks on
the message to go the website, the virus enters this new computer.
Certain viruses are less harmful, however, some are very harmful and can infect a computer in
the network through various ways (Simmonds 2004). A virus can corrupt the files or software
in a computer. Others may attack the computer hardware and bring the whole computer down.
Yet, some viruses may allow a person to have partial control of a computer, this allows for
unauthorized access to files and critical information stored in the computer’s hard drive.
Although the Windows platform is by far the most vulnerable, other operating systems can also
be attacked by viruses.
Network threats arising from viruses can be managed through various ways, however, the most
common technique is to install an antivirus software. UNIX-based systems such as Mac OS
and Linux are far more secure than Windows. Some anti-virus programs can scan file contents
and even zipped folders while some can also scan sent and received mails, a practice known as
‘on-access scanning’ (Simmonds 2004).Vulnerability to viruses can also be reduced by
carrying out data backups regularly on storage media that are not connected to the network or
computer. Security patches availed by software manufacturers can also assist in reducing
attacks by viruses. Secondary storage media must be scanned before opening in the host
computer.
Malware
Malware, short form of malicious software, is a program created to interrupt normal computer
operations or deny a user network or computer resources, gain partial control of the computer,
access files stored in the computer, gather network-based information such as passwords, and
other cruel or dishonest behavior (Curtin 1997).
Malware consists of a large number of malicious programs that includes viruses, Trojans
horses, worms, spyware, false adware, rootkits and other malicious programs. In 2009,
malware was listed as the second most dangerous threat to computer networks. Today, millions
of malware are created daily to exploit networks with weak security features.
Threats arising from malware can be removed using antivirus programs. Most antivirus have
an added feature of removing various malwares from the network of individual PCs. Besides,
anti-spyware software can be used to prevent spyware threats.
Denial-of-Service Attacks
A Denial-of-Service (DoS) attack is a practice aimed at making network resources unavailable
to some users. This vice entails the resolute efforts of a person or group of persons to prevent
an internet site or service functioning normally or bringing it down altogether. This network
threat is commonly committed against websites or services hosted on high profile internet
servers such as financial institutions and credit card payment services (Stallings 2010).
One mode of attack involves flooding a web server with requests in such a way that it cannot
respond to legitimate communication requests, or responds in a sluggish manner that virtually
renders it unusable. In general, DoS attacks are executed by either compelling the targeted
systems to reset, or using up its resources so that it is unable to offer the intended services.
DoS attacks are perhaps the most malicious and hardest to prevent or manage. They are the
most malicious due to the ease with which they can be launched and the difficulty of tracing
their origins, and it is difficult to deny the requests of the attacker without also blocking out
genuine requests for service.
DoS attacks can be prevented through various ways. The first technique is to use firewalls.
Firewalls have simple instructions of blocking or allowing certain IP addresses, or ports,
however, firewall are not very effective in some DoS attacks as they cannot distinguish
legitimate traffic from DoS traffic. Switches and routers can also be used to prevent these
attacks (Kizza 2006). Intrusion-prevention systems (IPS) have been successfully used to halt
DoS attacks that have signatures attached to them.
Unauthorized Access
This is a very wide terminology as it can refer to various types of attacks, however, the objective
of these attacks is to access some information that the computer or server is not supposed to
reveal. Unauthorized access to a computer or server can be achieved by using viruses, malware
and other malicious programs.
This form of threat can be waded off by using antivirus programs and security patches. Another
strategy used by intruders to access a computer on a network is a technique known as packet
sniffers. Packet sniffers can be used on a vulnerable network and they just ‘listen’ on the server
for words such as password or login in the packet stream, then sends the information thereafter
to the perpetrator.
This way, an intruder is able to obtain usernames, passwords, credit card information and other
critical information from unsuspecting users (Bragg et al 2010). This type of threat can be
prevented by using clear-text passwords, besides, data encryption can help divert such attacks.
When using a wireless network, it is advisable that one should use a long or complicated
password, also, it is advisable that the strongest security supported by the wireless connection
hardware should be used, such as encryption tools. Passwords can also be changed regularly.
General Methods for Preventing Network Attacks and Reducing Vulnerability on
Networks
The most commonly used technique for reducing network threats is the installation of antivirus
programs. These programs must be regularly updated and security patches and updates
installed. Improving the security of the network infrastructure can also involve switching on
features that enhance network security on switches, routers, and other hardware (Fadia 2006).
These security features ensure a secure connection, enhance perimeter security, prevents
intrusion, protects identity services, and general security management. Fixing intrusion
detection systems and firewalls offers protection for most areas of the network and allows for
a safe connection. Working on a virtual private network (VPN) can also enhance security. VPNs
provide network access control and encryption services.
Network security can also be improved by undertaking regular network security audits. A
network security audit simply means that an expert comes and examines the security of the
network, he also checks for loopholes that may be used attack the system and fixes them.
The audit can go beyond an inspection of the computers in the network and may comprise a
site assessment of the physical security of the organization. A network security audit fixes an
organization security flaws in the network and makes it difficult for perpetrators to attack the
network (Network Security Threats 2011).
Since network threats come in a variety of forms and cannot be totally eliminated, it is advisable
that secure updated data backups should be kept on systems that are detached from the network.
None of these strategies will singly eliminate the threats arising from a network connection,
but when they are used together, they can be exceedingly effectual at keeping a network safe.
Besides, well –thought-out organizational policies can be effective at preventing unauthorized
access to critical and parts of the network.
Introduction to Computer Networks
An elementary comprehension of computer networks is essential in order to understand the
codes of network security. A network is any set of interconnected lines, basing this definition
on the current topic, a computer network is basically a set of linked computers. Networks
enable users to share resources and information, and are classified base on a variety of protocols
(Network Security Threats 2011).For instance, a classification based on the connection manner
focuses on the hardware and software systems used to link the individual computer units, such
as optical fiber, wireless connection, or coaxial cable communication. Networks can also be
categorized on scale, this gives Local Area Network (LAN), wide area Network, virtual Private
Network (VPN), among others (Stallings 2010).
Networks are made up of ‘nodes’, which are the individual computers in the network, and at
least one server and/or ‘host’ computers. The nodes are linked together by communication
systems, which may be private, such as that within an institution, or can be accessed by the
public, such as the internet. Several private networks also use the internet.
The moment a computer network is instituted, it immediately becomes vulnerable to network
security threats such as viruses and bugs that may affect the normal functioning of a computer.
Besides, the personal information such as usernames, passwords, credit card numbers and other
critical information may be at risk if the computer does not have adequate security measures.
There are very many threats in a network, some of which are so severe and can bring down a
large network consisting of thousands of computers.
Virus
In the domain of computer networks, a virus refers to a computer program that can replicate
itself, similar to the biological virus. A computer virus spreads from one computer to another
through an executable program that attaches itself on programs, files and folders.
It can spread through various means, for example, if one computer in a network becomes
‘infected’ with a virus, the rest of the computers in the network may become infected too if the
security features are inadequate.
It can also be spread through USB devices, CD, DVD, or portable had drives. A computer virus
may also spread by mailing a web address link to all addresses so that when a person clicks on
the message to go the website, the virus enters this new computer.
Certain viruses are less harmful, however, some are very harmful and can infect a computer in
the network through various ways (Simmonds 2004). A virus can corrupt the files or software
in a computer. Others may attack the computer hardware and bring the whole computer down.
Yet, some viruses may allow a person to have partial control of a computer, this allows for
unauthorized access to files and critical information stored in the computer’s hard drive.
Although the Windows platform is by far the most vulnerable, other operating systems can also
be attacked by viruses.
Network threats arising from viruses can be managed through various ways, however, the most
common technique is to install an antivirus software. UNIX-based systems such as Mac OS
and Linux are far more secure than Windows. Some anti-virus programs can scan file contents
and even zipped folders while some can also scan sent and received mails, a practice known as
‘on-access scanning’ (Simmonds 2004).Vulnerability to viruses can also be reduced by
carrying out data backups regularly on storage media that are not connected to the network or
computer. Security patches availed by software manufacturers can also assist in reducing
attacks by viruses. Secondary storage media must be scanned before opening in the host
computer.
Malware
Malware, short form of malicious software, is a program created to interrupt normal computer
operations or deny a user network or computer resources, gain partial control of the computer,
access files stored in the computer, gather network-based information such as passwords, and
other cruel or dishonest behavior (Curtin 1997).
Malware consists of a large number of malicious programs that includes viruses, Trojans
horses, worms, spyware, false adware, rootkits and other malicious programs. In 2009,
malware was listed as the second most dangerous threat to computer networks. Today, millions
of malware are created daily to exploit networks with weak security features.
Threats arising from malware can be removed using antivirus programs. Most antivirus have
an added feature of removing various malwares from the network of individual PCs. Besides,
anti-spyware software can be used to prevent spyware threats.
Denial-of-Service Attacks
A Denial-of-Service (DoS) attack is a practice aimed at making network resources unavailable
to some users. This vice entails the resolute efforts of a person or group of persons to prevent
an internet site or service functioning normally or bringing it down altogether. This network
threat is commonly committed against websites or services hosted on high profile internet
servers such as financial institutions and credit card payment services (Stallings 2010).
One mode of attack involves flooding a web server with requests in such a way that it cannot
respond to legitimate communication requests, or responds in a sluggish manner that virtually
renders it unusable. In general, DoS attacks are executed by either compelling the targeted
systems to reset, or using up its resources so that it is unable to offer the intended services.
DoS attacks are perhaps the most malicious and hardest to prevent or manage. They are the
most malicious due to the ease with which they can be launched and the difficulty of tracing
their origins, and it is difficult to deny the requests of the attacker without also blocking out
genuine requests for service.
DoS attacks can be prevented through various ways. The first technique is to use firewalls.
Firewalls have simple instructions of blocking or allowing certain IP addresses, or ports,
however, firewall are not very effective in some DoS attacks as they cannot distinguish
legitimate traffic from DoS traffic. Switches and routers can also be used to prevent these
attacks (Kizza 2006). Intrusion-prevention systems (IPS) have been successfully used to halt
DoS attacks that have signatures attached to them.
Unauthorized Access
This is a very wide terminology as it can refer to various types of attacks, however, the objective
of these attacks is to access some information that the computer or server is not supposed to
reveal. Unauthorized access to a computer or server can be achieved by using viruses, malware
and other malicious programs.
This form of threat can be waded off by using antivirus programs and security patches. Another
strategy used by intruders to access a computer on a network is a technique known as packet
sniffers. Packet sniffers can be used on a vulnerable network and they just ‘listen’ on the server
for words such as password or login in the packet stream, then sends the information thereafter
to the perpetrator.
This way, an intruder is able to obtain usernames, passwords, credit card information and other
critical information from unsuspecting users (Bragg et al 2010). This type of threat can be
prevented by using clear-text passwords, besides, data encryption can help divert such attacks.
When using a wireless network, it is advisable that one should use a long or complicated
password, also, it is advisable that the strongest security supported by the wireless connection
hardware should be used, such as encryption tools. Passwords can also be changed regularly.
General Methods for Preventing Network Attacks and Reducing Vulnerability on
Networks
The most commonly used technique for reducing network threats is the installation of antivirus
programs. These programs must be regularly updated and security patches and updates
installed. Improving the security of the network infrastructure can also involve switching on
features that enhance network security on switches, routers, and other hardware (Fadia 2006).
These security features ensure a secure connection, enhance perimeter security, prevents
intrusion, protects identity services, and general security management. Fixing intrusion
detection systems and firewalls offers protection for most areas of the network and allows for
a safe connection. Working on a virtual private network (VPN) can also enhance security. VPNs
provide network access control and encryption services.
Network security can also be improved by undertaking regular network security audits. A
network security audit simply means that an expert comes and examines the security of the
network, he also checks for loopholes that may be used attack the system and fixes them.
The audit can go beyond an inspection of the computers in the network and may comprise a
site assessment of the physical security of the organization. A network security audit fixes an
organization security flaws in the network and makes it difficult for perpetrators to attack the
network (Network Security Threats 2011).
Since network threats come in a variety of forms and cannot be totally eliminated, it is advisable
that secure updated data backups should be kept on systems that are detached from the network.
None of these strategies will singly eliminate the threats arising from a network connection,
but when they are used together, they can be exceedingly effectual at keeping a network safe.
Besides, well –thought-out organizational policies can be effective at preventing unauthorized
access to critical and parts of the network.
Introduction to Computer Networks
An elementary comprehension of computer networks is essential in order to understand the
codes of network security. A network is any set of interconnected lines, basing this definition
on the current topic, a computer network is basically a set of linked computers. Networks
enable users to share resources and information, and are classified base on a variety of protocols
(Network Security Threats 2011).For instance, a classification based on the connection manner
focuses on the hardware and software systems used to link the individual computer units, such
as optical fiber, wireless connection, or coaxial cable communication. Networks can also be
categorized on scale, this gives Local Area Network (LAN), wide area Network, virtual Private
Network (VPN), among others (Stallings 2010).
Networks are made up of ‘nodes’, which are the individual computers in the network, and at
least one server and/or ‘host’ computers. The nodes are linked together by communication
systems, which may be private, such as that within an institution, or can be accessed by the
public, such as the internet. Several private networks also use the internet.
The moment a computer network is instituted, it immediately becomes vulnerable to network
security threats such as viruses and bugs that may affect the normal functioning of a computer.
Besides, the personal information such as usernames, passwords, credit card numbers and other
critical information may be at risk if the computer does not have adequate security measures.
There are very many threats in a network, some of which are so severe and can bring down a
large network consisting of thousands of computers.
Virus
In the domain of computer networks, a virus refers to a computer program that can replicate
itself, similar to the biological virus. A computer virus spreads from one computer to another
through an executable program that attaches itself on programs, files and folders.
It can spread through various means, for example, if one computer in a network becomes
‘infected’ with a virus, the rest of the computers in the network may become infected too if the
security features are inadequate.
It can also be spread through USB devices, CD, DVD, or portable had drives. A computer virus
may also spread by mailing a web address link to all addresses so that when a person clicks on
the message to go the website, the virus enters this new computer.
Certain viruses are less harmful, however, some are very harmful and can infect a computer in
the network through various ways (Simmonds 2004). A virus can corrupt the files or software
in a computer. Others may attack the computer hardware and bring the whole computer down.
Yet, some viruses may allow a person to have partial control of a computer, this allows for
unauthorized access to files and critical information stored in the computer’s hard drive.
Although the Windows platform is by far the most vulnerable, other operating systems can also
be attacked by viruses.
Network threats arising from viruses can be managed through various ways, however, the most
common technique is to install an antivirus software. UNIX-based systems such as Mac OS
and Linux are far more secure than Windows. Some anti-virus programs can scan file contents
and even zipped folders while some can also scan sent and received mails, a practice known as
‘on-access scanning’ (Simmonds 2004).Vulnerability to viruses can also be reduced by
carrying out data backups regularly on storage media that are not connected to the network or
computer. Security patches availed by software manufacturers can also assist in reducing
attacks by viruses. Secondary storage media must be scanned before opening in the host
computer.
Malware
Malware, short form of malicious software, is a program created to interrupt normal computer
operations or deny a user network or computer resources, gain partial control of the computer,
access files stored in the computer, gather network-based information such as passwords, and
other cruel or dishonest behavior (Curtin 1997).
Malware consists of a large number of malicious programs that includes viruses, Trojans
horses, worms, spyware, false adware, rootkits and other malicious programs. In 2009,
malware was listed as the second most dangerous threat to computer networks. Today, millions
of malware are created daily to exploit networks with weak security features.
Threats arising from malware can be removed using antivirus programs. Most antivirus have
an added feature of removing various malwares from the network of individual PCs. Besides,
anti-spyware software can be used to prevent spyware threats.
Denial-of-Service Attacks
A Denial-of-Service (DoS) attack is a practice aimed at making network resources unavailable
to some users. This vice entails the resolute efforts of a person or group of persons to prevent
an internet site or service functioning normally or bringing it down altogether. This network
threat is commonly committed against websites or services hosted on high profile internet
servers such as financial institutions and credit card payment services (Stallings 2010).
One mode of attack involves flooding a web server with requests in such a way that it cannot
respond to legitimate communication requests, or responds in a sluggish manner that virtually
renders it unusable. In general, DoS attacks are executed by either compelling the targeted
systems to reset, or using up its resources so that it is unable to offer the intended services.
DoS attacks are perhaps the most malicious and hardest to prevent or manage. They are the
most malicious due to the ease with which they can be launched and the difficulty of tracing
their origins, and it is difficult to deny the requests of the attacker without also blocking out
genuine requests for service.
DoS attacks can be prevented through various ways. The first technique is to use firewalls.
Firewalls have simple instructions of blocking or allowing certain IP addresses, or ports,
however, firewall are not very effective in some DoS attacks as they cannot distinguish
legitimate traffic from DoS traffic. Switches and routers can also be used to prevent these
attacks (Kizza 2006). Intrusion-prevention systems (IPS) have been successfully used to halt
DoS attacks that have signatures attached to them.
Unauthorized Access
This is a very wide terminology as it can refer to various types of attacks, however, the objective
of these attacks is to access some information that the computer or server is not supposed to
reveal. Unauthorized access to a computer or server can be achieved by using viruses, malware
and other malicious programs.
This form of threat can be waded off by using antivirus programs and security patches. Another
strategy used by intruders to access a computer on a network is a technique known as packet
sniffers. Packet sniffers can be used on a vulnerable network and they just ‘listen’ on the server
for words such as password or login in the packet stream, then sends the information thereafter
to the perpetrator.
This way, an intruder is able to obtain usernames, passwords, credit card information and other
critical information from unsuspecting users (Bragg et al 2010). This type of threat can be
prevented by using clear-text passwords, besides, data encryption can help divert such attacks.
When using a wireless network, it is advisable that one should use a long or complicated
password, also, it is advisable that the strongest security supported by the wireless connection
hardware should be used, such as encryption tools. Passwords can also be changed regularly.
General Methods for Preventing Network Attacks and Reducing Vulnerability on
Networks
The most commonly used technique for reducing network threats is the installation of antivirus
programs. These programs must be regularly updated and security patches and updates
installed. Improving the security of the network infrastructure can also involve switching on
features that enhance network security on switches, routers, and other hardware (Fadia 2006).
These security features ensure a secure connection, enhance perimeter security, prevents
intrusion, protects identity services, and general security management. Fixing intrusion
detection systems and firewalls offers protection for most areas of the network and allows for
a safe connection. Working on a virtual private network (VPN) can also enhance security. VPNs
provide network access control and encryption services.
Network security can also be improved by undertaking regular network security audits. A
network security audit simply means that an expert comes and examines the security of the
network, he also checks for loopholes that may be used attack the system and fixes them.
The audit can go beyond an inspection of the computers in the network and may comprise a
site assessment of the physical security of the organization. A network security audit fixes an
organization security flaws in the network and makes it difficult for perpetrators to attack the
network (Network Security Threats 2011).
Since network threats come in a variety of forms and cannot be totally eliminated, it is advisable
that secure updated data backups should be kept on systems that are detached from the network.
None of these strategies will singly eliminate the threats arising from a network connection,
but when they are used together, they can be exceedingly effectual at keeping a network safe.
Besides, well –thought-out organizational policies can be effective at preventing unauthorized
access to critical and parts of the network.
Introduction to Computer Networks
An elementary comprehension of computer networks is essential in order to understand the
codes of network security. A network is any set of interconnected lines, basing this definition
on the current topic, a computer network is basically a set of linked computers. Networks
enable users to share resources and information, and are classified base on a variety of protocols
(Network Security Threats 2011).For instance, a classification based on the connection manner
focuses on the hardware and software systems used to link the individual computer units, such
as optical fiber, wireless connection, or coaxial cable communication. Networks can also be
categorized on scale, this gives Local Area Network (LAN), wide area Network, virtual Private
Network (VPN), among others (Stallings 2010).
Networks are made up of ‘nodes’, which are the individual computers in the network, and at
least one server and/or ‘host’ computers. The nodes are linked together by communication
systems, which may be private, such as that within an institution, or can be accessed by the
public, such as the internet. Several private networks also use the internet.
The moment a computer network is instituted, it immediately becomes vulnerable to network
security threats such as viruses and bugs that may affect the normal functioning of a computer.
Besides, the personal information such as usernames, passwords, credit card numbers and other
critical information may be at risk if the computer does not have adequate security measures.
There are very many threats in a network, some of which are so severe and can bring down a
large network consisting of thousands of computers.
Virus
In the domain of computer networks, a virus refers to a computer program that can replicate
itself, similar to the biological virus. A computer virus spreads from one computer to another
through an executable program that attaches itself on programs, files and folders.
It can spread through various means, for example, if one computer in a network becomes
‘infected’ with a virus, the rest of the computers in the network may become infected too if the
security features are inadequate.
It can also be spread through USB devices, CD, DVD, or portable had drives. A computer virus
may also spread by mailing a web address link to all addresses so that when a person clicks on
the message to go the website, the virus enters this new computer.
Certain viruses are less harmful, however, some are very harmful and can infect a computer in
the network through various ways (Simmonds 2004). A virus can corrupt the files or software
in a computer. Others may attack the computer hardware and bring the whole computer down.
Yet, some viruses may allow a person to have partial control of a computer, this allows for
unauthorized access to files and critical information stored in the computer’s hard drive.
Although the Windows platform is by far the most vulnerable, other operating systems can also
be attacked by viruses.
Network threats arising from viruses can be managed through various ways, however, the most
common technique is to install an antivirus software. UNIX-based systems such as Mac OS
and Linux are far more secure than Windows. Some anti-virus programs can scan file contents
and even zipped folders while some can also scan sent and received mails, a practice known as
‘on-access scanning’ (Simmonds 2004).Vulnerability to viruses can also be reduced by
carrying out data backups regularly on storage media that are not connected to the network or
computer. Security patches availed by software manufacturers can also assist in reducing
attacks by viruses. Secondary storage media must be scanned before opening in the host
computer.
Malware
Malware, short form of malicious software, is a program created to interrupt normal computer
operations or deny a user network or computer resources, gain partial control of the computer,
access files stored in the computer, gather network-based information such as passwords, and
other cruel or dishonest behavior (Curtin 1997).
Malware consists of a large number of malicious programs that includes viruses, Trojans
horses, worms, spyware, false adware, rootkits and other malicious programs. In 2009,
malware was listed as the second most dangerous threat to computer networks. Today, millions
of malware are created daily to exploit networks with weak security features.
Threats arising from malware can be removed using antivirus programs. Most antivirus have
an added feature of removing various malwares from the network of individual PCs. Besides,
anti-spyware software can be used to prevent spyware threats.
Denial-of-Service Attacks
A Denial-of-Service (DoS) attack is a practice aimed at making network resources unavailable
to some users. This vice entails the resolute efforts of a person or group of persons to prevent
an internet site or service functioning normally or bringing it down altogether. This network
threat is commonly committed against websites or services hosted on high profile internet
servers such as financial institutions and credit card payment services (Stallings 2010).
One mode of attack involves flooding a web server with requests in such a way that it cannot
respond to legitimate communication requests, or responds in a sluggish manner that virtually
renders it unusable. In general, DoS attacks are executed by either compelling the targeted
systems to reset, or using up its resources so that it is unable to offer the intended services.
DoS attacks are perhaps the most malicious and hardest to prevent or manage. They are the
most malicious due to the ease with which they can be launched and the difficulty of tracing
their origins, and it is difficult to deny the requests of the attacker without also blocking out
genuine requests for service.
DoS attacks can be prevented through various ways. The first technique is to use firewalls.
Firewalls have simple instructions of blocking or allowing certain IP addresses, or ports,
however, firewall are not very effective in some DoS attacks as they cannot distinguish
legitimate traffic from DoS traffic. Switches and routers can also be used to prevent these
attacks (Kizza 2006). Intrusion-prevention systems (IPS) have been successfully used to halt
DoS attacks that have signatures attached to them.
Unauthorized Access
This is a very wide terminology as it can refer to various types of attacks, however, the objective
of these attacks is to access some information that the computer or server is not supposed to
reveal. Unauthorized access to a computer or server can be achieved by using viruses, malware
and other malicious programs.
This form of threat can be waded off by using antivirus programs and security patches. Another
strategy used by intruders to access a computer on a network is a technique known as packet
sniffers. Packet sniffers can be used on a vulnerable network and they just ‘listen’ on the server
for words such as password or login in the packet stream, then sends the information thereafter
to the perpetrator.
This way, an intruder is able to obtain usernames, passwords, credit card information and other
critical information from unsuspecting users (Bragg et al 2010). This type of threat can be
prevented by using clear-text passwords, besides, data encryption can help divert such attacks.
When using a wireless network, it is advisable that one should use a long or complicated
password, also, it is advisable that the strongest security supported by the wireless connection
hardware should be used, such as encryption tools. Passwords can also be changed regularly.
General Methods for Preventing Network Attacks and Reducing Vulnerability on
Networks
The most commonly used technique for reducing network threats is the installation of antivirus
programs. These programs must be regularly updated and security patches and updates
installed. Improving the security of the network infrastructure can also involve switching on
features that enhance network security on switches, routers, and other hardware (Fadia 2006).
These security features ensure a secure connection, enhance perimeter security, prevents
intrusion, protects identity services, and general security management. Fixing intrusion
detection systems and firewalls offers protection for most areas of the network and allows for
a safe connection. Working on a virtual private network (VPN) can also enhance security. VPNs
provide network access control and encryption services.
Network security can also be improved by undertaking regular network security audits. A
network security audit simply means that an expert comes and examines the security of the
network, he also checks for loopholes that may be used attack the system and fixes them.
The audit can go beyond an inspection of the computers in the network and may comprise a
site assessment of the physical security of the organization. A network security audit fixes an
organization security flaws in the network and makes it difficult for perpetrators to attack the
network (Network Security Threats 2011).
Since network threats come in a variety of forms and cannot be totally eliminated, it is advisable
that secure updated data backups should be kept on systems that are detached from the network.
None of these strategies will singly eliminate the threats arising from a network connection,
but when they are used together, they can be exceedingly effectual at keeping a network safe.
Besides, well –thought-out organizational policies can be effective at preventing unauthorized
access to critical and parts of the network.
Introduction to Computer Networks
An elementary comprehension of computer networks is essential in order to understand the
codes of network security. A network is any set of interconnected lines, basing this definition
on the current topic, a computer network is basically a set of linked computers. Networks
enable users to share resources and information, and are classified base on a variety of protocols
(Network Security Threats 2011).For instance, a classification based on the connection manner
focuses on the hardware and software systems used to link the individual computer units, such
as optical fiber, wireless connection, or coaxial cable communication. Networks can also be
categorized on scale, this gives Local Area Network (LAN), wide area Network, virtual Private
Network (VPN), among others (Stallings 2010).
Networks are made up of ‘nodes’, which are the individual computers in the network, and at
least one server and/or ‘host’ computers. The nodes are linked together by communication
systems, which may be private, such as that within an institution, or can be accessed by the
public, such as the internet. Several private networks also use the internet.
The moment a computer network is instituted, it immediately becomes vulnerable to network
security threats such as viruses and bugs that may affect the normal functioning of a computer.
Besides, the personal information such as usernames, passwords, credit card numbers and other
critical information may be at risk if the computer does not have adequate security measures.
There are very many threats in a network, some of which are so severe and can bring down a
large network consisting of thousands of computers.
Virus
In the domain of computer networks, a virus refers to a computer program that can replicate
itself, similar to the biological virus. A computer virus spreads from one computer to another
through an executable program that attaches itself on programs, files and folders.
It can spread through various means, for example, if one computer in a network becomes
‘infected’ with a virus, the rest of the computers in the network may become infected too if the
security features are inadequate.
It can also be spread through USB devices, CD, DVD, or portable had drives. A computer virus
may also spread by mailing a web address link to all addresses so that when a person clicks on
the message to go the website, the virus enters this new computer.
Certain viruses are less harmful, however, some are very harmful and can infect a computer in
the network through various ways (Simmonds 2004). A virus can corrupt the files or software
in a computer. Others may attack the computer hardware and bring the whole computer down.
Yet, some viruses may allow a person to have partial control of a computer, this allows for
unauthorized access to files and critical information stored in the computer’s hard drive.
Although the Windows platform is by far the most vulnerable, other operating systems can also
be attacked by viruses.
Network threats arising from viruses can be managed through various ways, however, the most
common technique is to install an antivirus software. UNIX-based systems such as Mac OS
and Linux are far more secure than Windows. Some anti-virus programs can scan file contents
and even zipped folders while some can also scan sent and received mails, a practice known as
‘on-access scanning’ (Simmonds 2004).Vulnerability to viruses can also be reduced by
carrying out data backups regularly on storage media that are not connected to the network or
computer. Security patches availed by software manufacturers can also assist in reducing
attacks by viruses. Secondary storage media must be scanned before opening in the host
computer.
Malware
Malware, short form of malicious software, is a program created to interrupt normal computer
operations or deny a user network or computer resources, gain partial control of the computer,
access files stored in the computer, gather network-based information such as passwords, and
other cruel or dishonest behavior (Curtin 1997).
Malware consists of a large number of malicious programs that includes viruses, Trojans
horses, worms, spyware, false adware, rootkits and other malicious programs. In 2009,
malware was listed as the second most dangerous threat to computer networks. Today, millions
of malware are created daily to exploit networks with weak security features.
Threats arising from malware can be removed using antivirus programs. Most antivirus have
an added feature of removing various malwares from the network of individual PCs. Besides,
anti-spyware software can be used to prevent spyware threats.
Denial-of-Service Attacks
A Denial-of-Service (DoS) attack is a practice aimed at making network resources unavailable
to some users. This vice entails the resolute efforts of a person or group of persons to prevent
an internet site or service functioning normally or bringing it down altogether. This network
threat is commonly committed against websites or services hosted on high profile internet
servers such as financial institutions and credit card payment services (Stallings 2010).
One mode of attack involves flooding a web server with requests in such a way that it cannot
respond to legitimate communication requests, or responds in a sluggish manner that virtually
renders it unusable. In general, DoS attacks are executed by either compelling the targeted
systems to reset, or using up its resources so that it is unable to offer the intended services.
DoS attacks are perhaps the most malicious and hardest to prevent or manage. They are the
most malicious due to the ease with which they can be launched and the difficulty of tracing
their origins, and it is difficult to deny the requests of the attacker without also blocking out
genuine requests for service.
DoS attacks can be prevented through various ways. The first technique is to use firewalls.
Firewalls have simple instructions of blocking or allowing certain IP addresses, or ports,
however, firewall are not very effective in some DoS attacks as they cannot distinguish
legitimate traffic from DoS traffic. Switches and routers can also be used to prevent these
attacks (Kizza 2006). Intrusion-prevention systems (IPS) have been successfully used to halt
DoS attacks that have signatures attached to them.
Unauthorized Access
This is a very wide terminology as it can refer to various types of attacks, however, the objective
of these attacks is to access some information that the computer or server is not supposed to
reveal. Unauthorized access to a computer or server can be achieved by using viruses, malware
and other malicious programs.
This form of threat can be waded off by using antivirus programs and security patches. Another
strategy used by intruders to access a computer on a network is a technique known as packet
sniffers. Packet sniffers can be used on a vulnerable network and they just ‘listen’ on the server
for words such as password or login in the packet stream, then sends the information thereafter
to the perpetrator.
This way, an intruder is able to obtain usernames, passwords, credit card information and other
critical information from unsuspecting users (Bragg et al 2010). This type of threat can be
prevented by using clear-text passwords, besides, data encryption can help divert such attacks.
When using a wireless network, it is advisable that one should use a long or complicated
password, also, it is advisable that the strongest security supported by the wireless connection
hardware should be used, such as encryption tools. Passwords can also be changed regularly.
General Methods for Preventing Network Attacks and Reducing Vulnerability on
Networks
The most commonly used technique for reducing network threats is the installation of antivirus
programs. These programs must be regularly updated and security patches and updates
installed. Improving the security of the network infrastructure can also involve switching on
features that enhance network security on switches, routers, and other hardware (Fadia 2006).
These security features ensure a secure connection, enhance perimeter security, prevents
intrusion, protects identity services, and general security management. Fixing intrusion
detection systems and firewalls offers protection for most areas of the network and allows for
a safe connection. Working on a virtual private network (VPN) can also enhance security. VPNs
provide network access control and encryption services.
Network security can also be improved by undertaking regular network security audits. A
network security audit simply means that an expert comes and examines the security of the
network, he also checks for loopholes that may be used attack the system and fixes them.
The audit can go beyond an inspection of the computers in the network and may comprise a
site assessment of the physical security of the organization. A network security audit fixes an
organization security flaws in the network and makes it difficult for perpetrators to attack the
network (Network Security Threats 2011).
Since network threats come in a variety of forms and cannot be totally eliminated, it is advisable
that secure updated data backups should be kept on systems that are detached from the network.
None of these strategies will singly eliminate the threats arising from a network connection,
but when they are used together, they can be exceedingly effectual at keeping a network safe.
Besides, well –thought-out organizational policies can be effective at preventing unauthorized
access to critical and parts of the network.
Introduction to Computer Networks
An elementary comprehension of computer networks is essential in order to understand the
codes of network security. A network is any set of interconnected lines, basing this definition
on the current topic, a computer network is basically a set of linked computers. Networks
enable users to share resources and information, and are classified base on a variety of protocols
(Network Security Threats 2011).For instance, a classification based on the connection manner
focuses on the hardware and software systems used to link the individual computer units, such
as optical fiber, wireless connection, or coaxial cable communication. Networks can also be
categorized on scale, this gives Local Area Network (LAN), wide area Network, virtual Private
Network (VPN), among others (Stallings 2010).
Networks are made up of ‘nodes’, which are the individual computers in the network, and at
least one server and/or ‘host’ computers. The nodes are linked together by communication
systems, which may be private, such as that within an institution, or can be accessed by the
public, such as the internet. Several private networks also use the internet.
The moment a computer network is instituted, it immediately becomes vulnerable to network
security threats such as viruses and bugs that may affect the normal functioning of a computer.
Besides, the personal information such as usernames, passwords, credit card numbers and other
critical information may be at risk if the computer does not have adequate security measures.
There are very many threats in a network, some of which are so severe and can bring down a
large network consisting of thousands of computers.
Virus
In the domain of computer networks, a virus refers to a computer program that can replicate
itself, similar to the biological virus. A computer virus spreads from one computer to another
through an executable program that attaches itself on programs, files and folders.
It can spread through various means, for example, if one computer in a network becomes
‘infected’ with a virus, the rest of the computers in the network may become infected too if the
security features are inadequate.
It can also be spread through USB devices, CD, DVD, or portable had drives. A computer virus
may also spread by mailing a web address link to all addresses so that when a person clicks on
the message to go the website, the virus enters this new computer.
Certain viruses are less harmful, however, some are very harmful and can infect a computer in
the network through various ways (Simmonds 2004). A virus can corrupt the files or software
in a computer. Others may attack the computer hardware and bring the whole computer down.
Yet, some viruses may allow a person to have partial control of a computer, this allows for
unauthorized access to files and critical information stored in the computer’s hard drive.
Although the Windows platform is by far the most vulnerable, other operating systems can also
be attacked by viruses.
Network threats arising from viruses can be managed through various ways, however, the most
common technique is to install an antivirus software. UNIX-based systems such as Mac OS
and Linux are far more secure than Windows. Some anti-virus programs can scan file contents
and even zipped folders while some can also scan sent and received mails, a practice known as
‘on-access scanning’ (Simmonds 2004).Vulnerability to viruses can also be reduced by
carrying out data backups regularly on storage media that are not connected to the network or
computer. Security patches availed by software manufacturers can also assist in reducing
attacks by viruses. Secondary storage media must be scanned before opening in the host
computer.
Malware
Malware, short form of malicious software, is a program created to interrupt normal computer
operations or deny a user network or computer resources, gain partial control of the computer,
access files stored in the computer, gather network-based information such as passwords, and
other cruel or dishonest behavior (Curtin 1997).
Malware consists of a large number of malicious programs that includes viruses, Trojans
horses, worms, spyware, false adware, rootkits and other malicious programs. In 2009,
malware was listed as the second most dangerous threat to computer networks. Today, millions
of malware are created daily to exploit networks with weak security features.
Threats arising from malware can be removed using antivirus programs. Most antivirus have
an added feature of removing various malwares from the network of individual PCs. Besides,
anti-spyware software can be used to prevent spyware threats.
Denial-of-Service Attacks
A Denial-of-Service (DoS) attack is a practice aimed at making network resources unavailable
to some users. This vice entails the resolute efforts of a person or group of persons to prevent
an internet site or service functioning normally or bringing it down altogether. This network
threat is commonly committed against websites or services hosted on high profile internet
servers such as financial institutions and credit card payment services (Stallings 2010).
One mode of attack involves flooding a web server with requests in such a way that it cannot
respond to legitimate communication requests, or responds in a sluggish manner that virtually
renders it unusable. In general, DoS attacks are executed by either compelling the targeted
systems to reset, or using up its resources so that it is unable to offer the intended services.
DoS attacks are perhaps the most malicious and hardest to prevent or manage. They are the
most malicious due to the ease with which they can be launched and the difficulty of tracing
their origins, and it is difficult to deny the requests of the attacker without also blocking out
genuine requests for service.
DoS attacks can be prevented through various ways. The first technique is to use firewalls.
Firewalls have simple instructions of blocking or allowing certain IP addresses, or ports,
however, firewall are not very effective in some DoS attacks as they cannot distinguish
legitimate traffic from DoS traffic. Switches and routers can also be used to prevent these
attacks (Kizza 2006). Intrusion-prevention systems (IPS) have been successfully used to halt
DoS attacks that have signatures attached to them.
Unauthorized Access
This is a very wide terminology as it can refer to various types of attacks, however, the objective
of these attacks is to access some information that the computer or server is not supposed to
reveal. Unauthorized access to a computer or server can be achieved by using viruses, malware
and other malicious programs.
This form of threat can be waded off by using antivirus programs and security patches. Another
strategy used by intruders to access a computer on a network is a technique known as packet
sniffers. Packet sniffers can be used on a vulnerable network and they just ‘listen’ on the server
for words such as password or login in the packet stream, then sends the information thereafter
to the perpetrator.
This way, an intruder is able to obtain usernames, passwords, credit card information and other
critical information from unsuspecting users (Bragg et al 2010). This type of threat can be
prevented by using clear-text passwords, besides, data encryption can help divert such attacks.
When using a wireless network, it is advisable that one should use a long or complicated
password, also, it is advisable that the strongest security supported by the wireless connection
hardware should be used, such as encryption tools. Passwords can also be changed regularly.
General Methods for Preventing Network Attacks and Reducing Vulnerability on
Networks
The most commonly used technique for reducing network threats is the installation of antivirus
programs. These programs must be regularly updated and security patches and updates
installed. Improving the security of the network infrastructure can also involve switching on
features that enhance network security on switches, routers, and other hardware (Fadia 2006).
These security features ensure a secure connection, enhance perimeter security, prevents
intrusion, protects identity services, and general security management. Fixing intrusion
detection systems and firewalls offers protection for most areas of the network and allows for
a safe connection. Working on a virtual private network (VPN) can also enhance security. VPNs
provide network access control and encryption services.
Network security can also be improved by undertaking regular network security audits. A
network security audit simply means that an expert comes and examines the security of the
network, he also checks for loopholes that may be used attack the system and fixes them.
The audit can go beyond an inspection of the computers in the network and may comprise a
site assessment of the physical security of the organization. A network security audit fixes an
organization security flaws in the network and makes it difficult for perpetrators to attack the
network (Network Security Threats 2011).
Since network threats come in a variety of forms and cannot be totally eliminated, it is advisable
that secure updated data backups should be kept on systems that are detached from the network.
None of these strategies will singly eliminate the threats arising from a network connection,
but when they are used together, they can be exceedingly effectual at keeping a network safe.
Besides, well –thought-out organizational policies can be effective at preventing unauthorized
access to critical and parts of the network.
Introduction to Computer Networks
An elementary comprehension of computer networks is essential in order to understand the
codes of network security. A network is any set of interconnected lines, basing this definition
on the current topic, a computer network is basically a set of linked computers. Networks
enable users to share resources and information, and are classified base on a variety of protocols
(Network Security Threats 2011).For instance, a classification based on the connection manner
focuses on the hardware and software systems used to link the individual computer units, such
as optical fiber, wireless connection, or coaxial cable communication. Networks can also be
categorized on scale, this gives Local Area Network (LAN), wide area Network, virtual Private
Network (VPN), among others (Stallings 2010).
Networks are made up of ‘nodes’, which are the individual computers in the network, and at
least one server and/or ‘host’ computers. The nodes are linked together by communication
systems, which may be private, such as that within an institution, or can be accessed by the
public, such as the internet. Several private networks also use the internet.
The moment a computer network is instituted, it immediately becomes vulnerable to network
security threats such as viruses and bugs that may affect the normal functioning of a computer.
Besides, the personal information such as usernames, passwords, credit card numbers and other
critical information may be at risk if the computer does not have adequate security measures.
There are very many threats in a network, some of which are so severe and can bring down a
large network consisting of thousands of computers.
Virus
In the domain of computer networks, a virus refers to a computer program that can replicate
itself, similar to the biological virus. A computer virus spreads from one computer to another
through an executable program that attaches itself on programs, files and folders.
It can spread through various means, for example, if one computer in a network becomes
‘infected’ with a virus, the rest of the computers in the network may become infected too if the
security features are inadequate.
It can also be spread through USB devices, CD, DVD, or portable had drives. A computer virus
may also spread by mailing a web address link to all addresses so that when a person clicks on
the message to go the website, the virus enters this new computer.
Certain viruses are less harmful, however, some are very harmful and can infect a computer in
the network through various ways (Simmonds 2004). A virus can corrupt the files or software
in a computer. Others may attack the computer hardware and bring the whole computer down.
Yet, some viruses may allow a person to have partial control of a computer, this allows for
unauthorized access to files and critical information stored in the computer’s hard drive.
Although the Windows platform is by far the most vulnerable, other operating systems can also
be attacked by viruses.
Network threats arising from viruses can be managed through various ways, however, the most
common technique is to install an antivirus software. UNIX-based systems such as Mac OS
and Linux are far more secure than Windows. Some anti-virus programs can scan file contents
and even zipped folders while some can also scan sent and received mails, a practice known as
‘on-access scanning’ (Simmonds 2004).Vulnerability to viruses can also be reduced by
carrying out data backups regularly on storage media that are not connected to the network or
computer. Security patches availed by software manufacturers can also assist in reducing
attacks by viruses. Secondary storage media must be scanned before opening in the host
computer.
Malware
Malware, short form of malicious software, is a program created to interrupt normal computer
operations or deny a user network or computer resources, gain partial control of the computer,
access files stored in the computer, gather network-based information such as passwords, and
other cruel or dishonest behavior (Curtin 1997).
Malware consists of a large number of malicious programs that includes viruses, Trojans
horses, worms, spyware, false adware, rootkits and other malicious programs. In 2009,
malware was listed as the second most dangerous threat to computer networks. Today, millions
of malware are created daily to exploit networks with weak security features.
Threats arising from malware can be removed using antivirus programs. Most antivirus have
an added feature of removing various malwares from the network of individual PCs. Besides,
anti-spyware software can be used to prevent spyware threats.
Denial-of-Service Attacks
A Denial-of-Service (DoS) attack is a practice aimed at making network resources unavailable
to some users. This vice entails the resolute efforts of a person or group of persons to prevent
an internet site or service functioning normally or bringing it down altogether. This network
threat is commonly committed against websites or services hosted on high profile internet
servers such as financial institutions and credit card payment services (Stallings 2010).
One mode of attack involves flooding a web server with requests in such a way that it cannot
respond to legitimate communication requests, or responds in a sluggish manner that virtually
renders it unusable. In general, DoS attacks are executed by either compelling the targeted
systems to reset, or using up its resources so that it is unable to offer the intended services.
DoS attacks are perhaps the most malicious and hardest to prevent or manage. They are the
most malicious due to the ease with which they can be launched and the difficulty of tracing
their origins, and it is difficult to deny the requests of the attacker without also blocking out
genuine requests for service.
DoS attacks can be prevented through various ways. The first technique is to use firewalls.
Firewalls have simple instructions of blocking or allowing certain IP addresses, or ports,
however, firewall are not very effective in some DoS attacks as they cannot distinguish
legitimate traffic from DoS traffic. Switches and routers can also be used to prevent these
attacks (Kizza 2006). Intrusion-prevention systems (IPS) have been successfully used to halt
DoS attacks that have signatures attached to them.
Unauthorized Access
This is a very wide terminology as it can refer to various types of attacks, however, the objective
of these attacks is to access some information that the computer or server is not supposed to
reveal. Unauthorized access to a computer or server can be achieved by using viruses, malware
and other malicious programs.
This form of threat can be waded off by using antivirus programs and security patches. Another
strategy used by intruders to access a computer on a network is a technique known as packet
sniffers. Packet sniffers can be used on a vulnerable network and they just ‘listen’ on the server
for words such as password or login in the packet stream, then sends the information thereafter
to the perpetrator.
This way, an intruder is able to obtain usernames, passwords, credit card information and other
critical information from unsuspecting users (Bragg et al 2010). This type of threat can be
prevented by using clear-text passwords, besides, data encryption can help divert such attacks.
When using a wireless network, it is advisable that one should use a long or complicated
password, also, it is advisable that the strongest security supported by the wireless connection
hardware should be used, such as encryption tools. Passwords can also be changed regularly.
General Methods for Preventing Network Attacks and Reducing Vulnerability on
Networks
The most commonly used technique for reducing network threats is the installation of antivirus
programs. These programs must be regularly updated and security patches and updates
installed. Improving the security of the network infrastructure can also involve switching on
features that enhance network security on switches, routers, and other hardware (Fadia 2006).
These security features ensure a secure connection, enhance perimeter security, prevents
intrusion, protects identity services, and general security management. Fixing intrusion
detection systems and firewalls offers protection for most areas of the network and allows for
a safe connection. Working on a virtual private network (VPN) can also enhance security. VPNs
provide network access control and encryption services.
Network security can also be improved by undertaking regular network security audits. A
network security audit simply means that an expert comes and examines the security of the
network, he also checks for loopholes that may be used attack the system and fixes them.
The audit can go beyond an inspection of the computers in the network and may comprise a
site assessment of the physical security of the organization. A network security audit fixes an
organization security flaws in the network and makes it difficult for perpetrators to attack the
network (Network Security Threats 2011).
Since network threats come in a variety of forms and cannot be totally eliminated, it is advisable
that secure updated data backups should be kept on systems that are detached from the network.
None of these strategies will singly eliminate the threats arising from a network connection,
but when they are used together, they can be exceedingly effectual at keeping a network safe.
Besides, well –thought-out organizational policies can be effective at preventing unauthorized
access to critical and parts of the network.
Introduction to Computer Networks
An elementary comprehension of computer networks is essential in order to understand the
codes of network security. A network is any set of interconnected lines, basing this definition
on the current topic, a computer network is basically a set of linked computers. Networks
enable users to share resources and information, and are classified base on a variety of protocols
(Network Security Threats 2011).For instance, a classification based on the connection manner
focuses on the hardware and software systems used to link the individual computer units, such
as optical fiber, wireless connection, or coaxial cable communication. Networks can also be
categorized on scale, this gives Local Area Network (LAN), wide area Network, virtual Private
Network (VPN), among others (Stallings 2010).
Networks are made up of ‘nodes’, which are the individual computers in the network, and at
least one server and/or ‘host’ computers. The nodes are linked together by communication
systems, which may be private, such as that within an institution, or can be accessed by the
public, such as the internet. Several private networks also use the internet.
The moment a computer network is instituted, it immediately becomes vulnerable to network
security threats such as viruses and bugs that may affect the normal functioning of a computer.
Besides, the personal information such as usernames, passwords, credit card numbers and other
critical information may be at risk if the computer does not have adequate security measures.
There are very many threats in a network, some of which are so severe and can bring down a
large network consisting of thousands of computers.
Virus
In the domain of computer networks, a virus refers to a computer program that can replicate
itself, similar to the biological virus. A computer virus spreads from one computer to another
through an executable program that attaches itself on programs, files and folders.
It can spread through various means, for example, if one computer in a network becomes
‘infected’ with a virus, the rest of the computers in the network may become infected too if the
security features are inadequate.
It can also be spread through USB devices, CD, DVD, or portable had drives. A computer virus
may also spread by mailing a web address link to all addresses so that when a person clicks on
the message to go the website, the virus enters this new computer.
Certain viruses are less harmful, however, some are very harmful and can infect a computer in
the network through various ways (Simmonds 2004). A virus can corrupt the files or software
in a computer. Others may attack the computer hardware and bring the whole computer down.
Yet, some viruses may allow a person to have partial control of a computer, this allows for
unauthorized access to files and critical information stored in the computer’s hard drive.
Although the Windows platform is by far the most vulnerable, other operating systems can also
be attacked by viruses.
Network threats arising from viruses can be managed through various ways, however, the most
common technique is to install an antivirus software. UNIX-based systems such as Mac OS
and Linux are far more secure than Windows. Some anti-virus programs can scan file contents
and even zipped folders while some can also scan sent and received mails, a practice known as
‘on-access scanning’ (Simmonds 2004).Vulnerability to viruses can also be reduced by
carrying out data backups regularly on storage media that are not connected to the network or
computer. Security patches availed by software manufacturers can also assist in reducing
attacks by viruses. Secondary storage media must be scanned before opening in the host
computer.
Malware
Malware, short form of malicious software, is a program created to interrupt normal computer
operations or deny a user network or computer resources, gain partial control of the computer,
access files stored in the computer, gather network-based information such as passwords, and
other cruel or dishonest behavior (Curtin 1997).
Malware consists of a large number of malicious programs that includes viruses, Trojans
horses, worms, spyware, false adware, rootkits and other malicious programs. In 2009,
malware was listed as the second most dangerous threat to computer networks. Today, millions
of malware are created daily to exploit networks with weak security features.
Threats arising from malware can be removed using antivirus programs. Most antivirus have
an added feature of removing various malwares from the network of individual PCs. Besides,
anti-spyware software can be used to prevent spyware threats.
Denial-of-Service Attacks
A Denial-of-Service (DoS) attack is a practice aimed at making network resources unavailable
to some users. This vice entails the resolute efforts of a person or group of persons to prevent
an internet site or service functioning normally or bringing it down altogether. This network
threat is commonly committed against websites or services hosted on high profile internet
servers such as financial institutions and credit card payment services (Stallings 2010).
One mode of attack involves flooding a web server with requests in such a way that it cannot
respond to legitimate communication requests, or responds in a sluggish manner that virtually
renders it unusable. In general, DoS attacks are executed by either compelling the targeted
systems to reset, or using up its resources so that it is unable to offer the intended services.
DoS attacks are perhaps the most malicious and hardest to prevent or manage. They are the
most malicious due to the ease with which they can be launched and the difficulty of tracing
their origins, and it is difficult to deny the requests of the attacker without also blocking out
genuine requests for service.
DoS attacks can be prevented through various ways. The first technique is to use firewalls.
Firewalls have simple instructions of blocking or allowing certain IP addresses, or ports,
however, firewall are not very effective in some DoS attacks as they cannot distinguish
legitimate traffic from DoS traffic. Switches and routers can also be used to prevent these
attacks (Kizza 2006). Intrusion-prevention systems (IPS) have been successfully used to halt
DoS attacks that have signatures attached to them.
Unauthorized Access
This is a very wide terminology as it can refer to various types of attacks, however, the objective
of these attacks is to access some information that the computer or server is not supposed to
reveal. Unauthorized access to a computer or server can be achieved by using viruses, malware
and other malicious programs.
This form of threat can be waded off by using antivirus programs and security patches. Another
strategy used by intruders to access a computer on a network is a technique known as packet
sniffers. Packet sniffers can be used on a vulnerable network and they just ‘listen’ on the server
for words such as password or login in the packet stream, then sends the information thereafter
to the perpetrator.
This way, an intruder is able to obtain usernames, passwords, credit card information and other
critical information from unsuspecting users (Bragg et al 2010). This type of threat can be
prevented by using clear-text passwords, besides, data encryption can help divert such attacks.
When using a wireless network, it is advisable that one should use a long or complicated
password, also, it is advisable that the strongest security supported by the wireless connection
hardware should be used, such as encryption tools. Passwords can also be changed regularly.
General Methods for Preventing Network Attacks and Reducing Vulnerability on
Networks
The most commonly used technique for reducing network threats is the installation of antivirus
programs. These programs must be regularly updated and security patches and updates
installed. Improving the security of the network infrastructure can also involve switching on
features that enhance network security on switches, routers, and other hardware (Fadia 2006).
These security features ensure a secure connection, enhance perimeter security, prevents
intrusion, protects identity services, and general security management. Fixing intrusion
detection systems and firewalls offers protection for most areas of the network and allows for
a safe connection. Working on a virtual private network (VPN) can also enhance security. VPNs
provide network access control and encryption services.
Network security can also be improved by undertaking regular network security audits. A
network security audit simply means that an expert comes and examines the security of the
network, he also checks for loopholes that may be used attack the system and fixes them.
The audit can go beyond an inspection of the computers in the network and may comprise a
site assessment of the physical security of the organization. A network security audit fixes an
organization security flaws in the network and makes it difficult for perpetrators to attack the
network (Network Security Threats 2011).
Since network threats come in a variety of forms and cannot be totally eliminated, it is advisable
that secure updated data backups should be kept on systems that are detached from the network.
None of these strategies will singly eliminate the threats arising from a network connection,
but when they are used together, they can be exceedingly effectual at keeping a network safe.
Besides, well –thought-out organizational policies can be effective at preventing unauthorized
access to critical and parts of the network.
Introduction to Computer Networks
An elementary comprehension of computer networks is essential in order to understand the
codes of network security. A network is any set of interconnected lines, basing this definition
on the current topic, a computer network is basically a set of linked computers. Networks
enable users to share resources and information, and are classified base on a variety of protocols
(Network Security Threats 2011).For instance, a classification based on the connection manner
focuses on the hardware and software systems used to link the individual computer units, such
as optical fiber, wireless connection, or coaxial cable communication. Networks can also be
categorized on scale, this gives Local Area Network (LAN), wide area Network, virtual Private
Network (VPN), among others (Stallings 2010).
Networks are made up of ‘nodes’, which are the individual computers in the network, and at
least one server and/or ‘host’ computers. The nodes are linked together by communication
systems, which may be private, such as that within an institution, or can be accessed by the
public, such as the internet. Several private networks also use the internet.
The moment a computer network is instituted, it immediately becomes vulnerable to network
security threats such as viruses and bugs that may affect the normal functioning of a computer.
Besides, the personal information such as usernames, passwords, credit card numbers and other
critical information may be at risk if the computer does not have adequate security measures.
There are very many threats in a network, some of which are so severe and can bring down a
large network consisting of thousands of computers.
Virus
In the domain of computer networks, a virus refers to a computer program that can replicate
itself, similar to the biological virus. A computer virus spreads from one computer to another
through an executable program that attaches itself on programs, files and folders.
It can spread through various means, for example, if one computer in a network becomes
‘infected’ with a virus, the rest of the computers in the network may become infected too if the
security features are inadequate.
It can also be spread through USB devices, CD, DVD, or portable had drives. A computer virus
may also spread by mailing a web address link to all addresses so that when a person clicks on
the message to go the website, the virus enters this new computer.
Certain viruses are less harmful, however, some are very harmful and can infect a computer in
the network through various ways (Simmonds 2004). A virus can corrupt the files or software
in a computer. Others may attack the computer hardware and bring the whole computer down.
Yet, some viruses may allow a person to have partial control of a computer, this allows for
unauthorized access to files and critical information stored in the computer’s hard drive.
Although the Windows platform is by far the most vulnerable, other operating systems can also
be attacked by viruses.
Network threats arising from viruses can be managed through various ways, however, the most
common technique is to install an antivirus software. UNIX-based systems such as Mac OS
and Linux are far more secure than Windows. Some anti-virus programs can scan file contents
and even zipped folders while some can also scan sent and received mails, a practice known as
‘on-access scanning’ (Simmonds 2004).Vulnerability to viruses can also be reduced by
carrying out data backups regularly on storage media that are not connected to the network or
computer. Security patches availed by software manufacturers can also assist in reducing
attacks by viruses. Secondary storage media must be scanned before opening in the host
computer.
Malware
Malware, short form of malicious software, is a program created to interrupt normal computer
operations or deny a user network or computer resources, gain partial control of the computer,
access files stored in the computer, gather network-based information such as passwords, and
other cruel or dishonest behavior (Curtin 1997).
Malware consists of a large number of malicious programs that includes viruses, Trojans
horses, worms, spyware, false adware, rootkits and other malicious programs. In 2009,
malware was listed as the second most dangerous threat to computer networks. Today, millions
of malware are created daily to exploit networks with weak security features.
Threats arising from malware can be removed using antivirus programs. Most antivirus have
an added feature of removing various malwares from the network of individual PCs. Besides,
anti-spyware software can be used to prevent spyware threats.
Denial-of-Service Attacks
A Denial-of-Service (DoS) attack is a practice aimed at making network resources unavailable
to some users. This vice entails the resolute efforts of a person or group of persons to prevent
an internet site or service functioning normally or bringing it down altogether. This network
threat is commonly committed against websites or services hosted on high profile internet
servers such as financial institutions and credit card payment services (Stallings 2010).
One mode of attack involves flooding a web server with requests in such a way that it cannot
respond to legitimate communication requests, or responds in a sluggish manner that virtually
renders it unusable. In general, DoS attacks are executed by either compelling the targeted
systems to reset, or using up its resources so that it is unable to offer the intended services.
DoS attacks are perhaps the most malicious and hardest to prevent or manage. They are the
most malicious due to the ease with which they can be launched and the difficulty of tracing
their origins, and it is difficult to deny the requests of the attacker without also blocking out
genuine requests for service.
DoS attacks can be prevented through various ways. The first technique is to use firewalls.
Firewalls have simple instructions of blocking or allowing certain IP addresses, or ports,
however, firewall are not very effective in some DoS attacks as they cannot distinguish
legitimate traffic from DoS traffic. Switches and routers can also be used to prevent these
attacks (Kizza 2006). Intrusion-prevention systems (IPS) have been successfully used to halt
DoS attacks that have signatures attached to them.
Unauthorized Access
This is a very wide terminology as it can refer to various types of attacks, however, the objective
of these attacks is to access some information that the computer or server is not supposed to
reveal. Unauthorized access to a computer or server can be achieved by using viruses, malware
and other malicious programs.
This form of threat can be waded off by using antivirus programs and security patches. Another
strategy used by intruders to access a computer on a network is a technique known as packet
sniffers. Packet sniffers can be used on a vulnerable network and they just ‘listen’ on the server
for words such as password or login in the packet stream, then sends the information thereafter
to the perpetrator.
This way, an intruder is able to obtain usernames, passwords, credit card information and other
critical information from unsuspecting users (Bragg et al 2010). This type of threat can be
prevented by using clear-text passwords, besides, data encryption can help divert such attacks.
When using a wireless network, it is advisable that one should use a long or complicated
password, also, it is advisable that the strongest security supported by the wireless connection
hardware should be used, such as encryption tools. Passwords can also be changed regularly.
General Methods for Preventing Network Attacks and Reducing Vulnerability on
Networks
The most commonly used technique for reducing network threats is the installation of antivirus
programs. These programs must be regularly updated and security patches and updates
installed. Improving the security of the network infrastructure can also involve switching on
features that enhance network security on switches, routers, and other hardware (Fadia 2006).
These security features ensure a secure connection, enhance perimeter security, prevents
intrusion, protects identity services, and general security management. Fixing intrusion
detection systems and firewalls offers protection for most areas of the network and allows for
a safe connection. Working on a virtual private network (VPN) can also enhance security. VPNs
provide network access control and encryption services.
Network security can also be improved by undertaking regular network security audits. A
network security audit simply means that an expert comes and examines the security of the
network, he also checks for loopholes that may be used attack the system and fixes them.
The audit can go beyond an inspection of the computers in the network and may comprise a
site assessment of the physical security of the organization. A network security audit fixes an
organization security flaws in the network and makes it difficult for perpetrators to attack the
network (Network Security Threats 2011).
Since network threats come in a variety of forms and cannot be totally eliminated, it is advisable
that secure updated data backups should be kept on systems that are detached from the network.
None of these strategies will singly eliminate the threats arising from a network connection,
but when they are used together, they can be exceedingly effectual at keeping a network safe.
Besides, well –thought-out organizational policies can be effective at preventing unauthorized
access to critical and parts of the network.
Introduction to Computer Networks
An elementary comprehension of computer networks is essential in order to understand the
codes of network security. A network is any set of interconnected lines, basing this definition
on the current topic, a computer network is basically a set of linked computers. Networks
enable users to share resources and information, and are classified base on a variety of protocols
(Network Security Threats 2011).For instance, a classification based on the connection manner
focuses on the hardware and software systems used to link the individual computer units, such
as optical fiber, wireless connection, or coaxial cable communication. Networks can also be
categorized on scale, this gives Local Area Network (LAN), wide area Network, virtual Private
Network (VPN), among others (Stallings 2010).
Networks are made up of ‘nodes’, which are the individual computers in the network, and at
least one server and/or ‘host’ computers. The nodes are linked together by communication
systems, which may be private, such as that within an institution, or can be accessed by the
public, such as the internet. Several private networks also use the internet.
The moment a computer network is instituted, it immediately becomes vulnerable to network
security threats such as viruses and bugs that may affect the normal functioning of a computer.
Besides, the personal information such as usernames, passwords, credit card numbers and other
critical information may be at risk if the computer does not have adequate security measures.
There are very many threats in a network, some of which are so severe and can bring down a
large network consisting of thousands of computers.
Virus
In the domain of computer networks, a virus refers to a computer program that can replicate
itself, similar to the biological virus. A computer virus spreads from one computer to another
through an executable program that attaches itself on programs, files and folders.
It can spread through various means, for example, if one computer in a network becomes
‘infected’ with a virus, the rest of the computers in the network may become infected too if the
security features are inadequate.
It can also be spread through USB devices, CD, DVD, or portable had drives. A computer virus
may also spread by mailing a web address link to all addresses so that when a person clicks on
the message to go the website, the virus enters this new computer.
Certain viruses are less harmful, however, some are very harmful and can infect a computer in
the network through various ways (Simmonds 2004). A virus can corrupt the files or software
in a computer. Others may attack the computer hardware and bring the whole computer down.
Yet, some viruses may allow a person to have partial control of a computer, this allows for
unauthorized access to files and critical information stored in the computer’s hard drive.
Although the Windows platform is by far the most vulnerable, other operating systems can also
be attacked by viruses.
Network threats arising from viruses can be managed through various ways, however, the most
common technique is to install an antivirus software. UNIX-based systems such as Mac OS
and Linux are far more secure than Windows. Some anti-virus programs can scan file contents
and even zipped folders while some can also scan sent and received mails, a practice known as
‘on-access scanning’ (Simmonds 2004).Vulnerability to viruses can also be reduced by
carrying out data backups regularly on storage media that are not connected to the network or
computer. Security patches availed by software manufacturers can also assist in reducing
attacks by viruses. Secondary storage media must be scanned before opening in the host
computer.
Malware
Malware, short form of malicious software, is a program created to interrupt normal computer
operations or deny a user network or computer resources, gain partial control of the computer,
access files stored in the computer, gather network-based information such as passwords, and
other cruel or dishonest behavior (Curtin 1997).
Malware consists of a large number of malicious programs that includes viruses, Trojans
horses, worms, spyware, false adware, rootkits and other malicious programs. In 2009,
malware was listed as the second most dangerous threat to computer networks. Today, millions
of malware are created daily to exploit networks with weak security features.
Threats arising from malware can be removed using antivirus programs. Most antivirus have
an added feature of removing various malwares from the network of individual PCs. Besides,
anti-spyware software can be used to prevent spyware threats.
Denial-of-Service Attacks
A Denial-of-Service (DoS) attack is a practice aimed at making network resources unavailable
to some users. This vice entails the resolute efforts of a person or group of persons to prevent
an internet site or service functioning normally or bringing it down altogether. This network
threat is commonly committed against websites or services hosted on high profile internet
servers such as financial institutions and credit card payment services (Stallings 2010).
One mode of attack involves flooding a web server with requests in such a way that it cannot
respond to legitimate communication requests, or responds in a sluggish manner that virtually
renders it unusable. In general, DoS attacks are executed by either compelling the targeted
systems to reset, or using up its resources so that it is unable to offer the intended services.
DoS attacks are perhaps the most malicious and hardest to prevent or manage. They are the
most malicious due to the ease with which they can be launched and the difficulty of tracing
their origins, and it is difficult to deny the requests of the attacker without also blocking out
genuine requests for service.
DoS attacks can be prevented through various ways. The first technique is to use firewalls.
Firewalls have simple instructions of blocking or allowing certain IP addresses, or ports,
however, firewall are not very effective in some DoS attacks as they cannot distinguish
legitimate traffic from DoS traffic. Switches and routers can also be used to prevent these
attacks (Kizza 2006). Intrusion-prevention systems (IPS) have been successfully used to halt
DoS attacks that have signatures attached to them.
Unauthorized Access
This is a very wide terminology as it can refer to various types of attacks, however, the objective
of these attacks is to access some information that the computer or server is not supposed to
reveal. Unauthorized access to a computer or server can be achieved by using viruses, malware
and other malicious programs.
This form of threat can be waded off by using antivirus programs and security patches. Another
strategy used by intruders to access a computer on a network is a technique known as packet
sniffers. Packet sniffers can be used on a vulnerable network and they just ‘listen’ on the server
for words such as password or login in the packet stream, then sends the information thereafter
to the perpetrator.
This way, an intruder is able to obtain usernames, passwords, credit card information and other
critical information from unsuspecting users (Bragg et al 2010). This type of threat can be
prevented by using clear-text passwords, besides, data encryption can help divert such attacks.
When using a wireless network, it is advisable that one should use a long or complicated
password, also, it is advisable that the strongest security supported by the wireless connection
hardware should be used, such as encryption tools. Passwords can also be changed regularly.
General Methods for Preventing Network Attacks and Reducing Vulnerability on
Networks
The most commonly used technique for reducing network threats is the installation of antivirus
programs. These programs must be regularly updated and security patches and updates
installed. Improving the security of the network infrastructure can also involve switching on
features that enhance network security on switches, routers, and other hardware (Fadia 2006).
These security features ensure a secure connection, enhance perimeter security, prevents
intrusion, protects identity services, and general security management. Fixing intrusion
detection systems and firewalls offers protection for most areas of the network and allows for
a safe connection. Working on a virtual private network (VPN) can also enhance security. VPNs
provide network access control and encryption services.
Network security can also be improved by undertaking regular network security audits. A
network security audit simply means that an expert comes and examines the security of the
network, he also checks for loopholes that may be used attack the system and fixes them.
The audit can go beyond an inspection of the computers in the network and may comprise a
site assessment of the physical security of the organization. A network security audit fixes an
organization security flaws in the network and makes it difficult for perpetrators to attack the
network (Network Security Threats 2011).
Since network threats come in a variety of forms and cannot be totally eliminated, it is advisable
that secure updated data backups should be kept on systems that are detached from the network.
None of these strategies will singly eliminate the threats arising from a network connection,
but when they are used together, they can be exceedingly effectual at keeping a network safe.
Besides, well –thought-out organizational policies can be effective at preventing unauthorized
access to critical and parts of the network.
Introduction to Computer Networks
An elementary comprehension of computer networks is essential in order to understand the
codes of network security. A network is any set of interconnected lines, basing this definition
on the current topic, a computer network is basically a set of linked computers. Networks
enable users to share resources and information, and are classified base on a variety of protocols
(Network Security Threats 2011).For instance, a classification based on the connection manner
focuses on the hardware and software systems used to link the individual computer units, such
as optical fiber, wireless connection, or coaxial cable communication. Networks can also be
categorized on scale, this gives Local Area Network (LAN), wide area Network, virtual Private
Network (VPN), among others (Stallings 2010).
Networks are made up of ‘nodes’, which are the individual computers in the network, and at
least one server and/or ‘host’ computers. The nodes are linked together by communication
systems, which may be private, such as that within an institution, or can be accessed by the
public, such as the internet. Several private networks also use the internet.
The moment a computer network is instituted, it immediately becomes vulnerable to network
security threats such as viruses and bugs that may affect the normal functioning of a computer.
Besides, the personal information such as usernames, passwords, credit card numbers and other
critical information may be at risk if the computer does not have adequate security measures.
There are very many threats in a network, some of which are so severe and can bring down a
large network consisting of thousands of computers.
Virus
In the domain of computer networks, a virus refers to a computer program that can replicate
itself, similar to the biological virus. A computer virus spreads from one computer to another
through an executable program that attaches itself on programs, files and folders.
It can spread through various means, for example, if one computer in a network becomes
‘infected’ with a virus, the rest of the computers in the network may become infected too if the
security features are inadequate.
It can also be spread through USB devices, CD, DVD, or portable had drives. A computer virus
may also spread by mailing a web address link to all addresses so that when a person clicks on
the message to go the website, the virus enters this new computer.
Certain viruses are less harmful, however, some are very harmful and can infect a computer in
the network through various ways (Simmonds 2004). A virus can corrupt the files or software
in a computer. Others may attack the computer hardware and bring the whole computer down.
Yet, some viruses may allow a person to have partial control of a computer, this allows for
unauthorized access to files and critical information stored in the computer’s hard drive.
Although the Windows platform is by far the most vulnerable, other operating systems can also
be attacked by viruses.
Network threats arising from viruses can be managed through various ways, however, the most
common technique is to install an antivirus software. UNIX-based systems such as Mac OS
and Linux are far more secure than Windows. Some anti-virus programs can scan file contents
and even zipped folders while some can also scan sent and received mails, a practice known as
‘on-access scanning’ (Simmonds 2004).Vulnerability to viruses can also be reduced by
carrying out data backups regularly on storage media that are not connected to the network or
computer. Security patches availed by software manufacturers can also assist in reducing
attacks by viruses. Secondary storage media must be scanned before opening in the host
computer.
Malware
Malware, short form of malicious software, is a program created to interrupt normal computer
operations or deny a user network or computer resources, gain partial control of the computer,
access files stored in the computer, gather network-based information such as passwords, and
other cruel or dishonest behavior (Curtin 1997).
Malware consists of a large number of malicious programs that includes viruses, Trojans
horses, worms, spyware, false adware, rootkits and other malicious programs. In 2009,
malware was listed as the second most dangerous threat to computer networks. Today, millions
of malware are created daily to exploit networks with weak security features.
Threats arising from malware can be removed using antivirus programs. Most antivirus have
an added feature of removing various malwares from the network of individual PCs. Besides,
anti-spyware software can be used to prevent spyware threats.
Denial-of-Service Attacks
A Denial-of-Service (DoS) attack is a practice aimed at making network resources unavailable
to some users. This vice entails the resolute efforts of a person or group of persons to prevent
an internet site or service functioning normally or bringing it down altogether. This network
threat is commonly committed against websites or services hosted on high profile internet
servers such as financial institutions and credit card payment services (Stallings 2010).
One mode of attack involves flooding a web server with requests in such a way that it cannot
respond to legitimate communication requests, or responds in a sluggish manner that virtually
renders it unusable. In general, DoS attacks are executed by either compelling the targeted
systems to reset, or using up its resources so that it is unable to offer the intended services.
DoS attacks are perhaps the most malicious and hardest to prevent or manage. They are the
most malicious due to the ease with which they can be launched and the difficulty of tracing
their origins, and it is difficult to deny the requests of the attacker without also blocking out
genuine requests for service.
DoS attacks can be prevented through various ways. The first technique is to use firewalls.
Firewalls have simple instructions of blocking or allowing certain IP addresses, or ports,
however, firewall are not very effective in some DoS attacks as they cannot distinguish
legitimate traffic from DoS traffic. Switches and routers can also be used to prevent these
attacks (Kizza 2006). Intrusion-prevention systems (IPS) have been successfully used to halt
DoS attacks that have signatures attached to them.
Unauthorized Access
This is a very wide terminology as it can refer to various types of attacks, however, the objective
of these attacks is to access some information that the computer or server is not supposed to
reveal. Unauthorized access to a computer or server can be achieved by using viruses, malware
and other malicious programs.
This form of threat can be waded off by using antivirus programs and security patches. Another
strategy used by intruders to access a computer on a network is a technique known as packet
sniffers. Packet sniffers can be used on a vulnerable network and they just ‘listen’ on the server
for words such as password or login in the packet stream, then sends the information thereafter
to the perpetrator.
This way, an intruder is able to obtain usernames, passwords, credit card information and other
critical information from unsuspecting users (Bragg et al 2010). This type of threat can be
prevented by using clear-text passwords, besides, data encryption can help divert such attacks.
When using a wireless network, it is advisable that one should use a long or complicated
password, also, it is advisable that the strongest security supported by the wireless connection
hardware should be used, such as encryption tools. Passwords can also be changed regularly.
General Methods for Preventing Network Attacks and Reducing Vulnerability on
Networks
The most commonly used technique for reducing network threats is the installation of antivirus
programs. These programs must be regularly updated and security patches and updates
installed. Improving the security of the network infrastructure can also involve switching on
features that enhance network security on switches, routers, and other hardware (Fadia 2006).
These security features ensure a secure connection, enhance perimeter security, prevents
intrusion, protects identity services, and general security management. Fixing intrusion
detection systems and firewalls offers protection for most areas of the network and allows for
a safe connection. Working on a virtual private network (VPN) can also enhance security. VPNs
provide network access control and encryption services.
Network security can also be improved by undertaking regular network security audits. A
network security audit simply means that an expert comes and examines the security of the
network, he also checks for loopholes that may be used attack the system and fixes them.
The audit can go beyond an inspection of the computers in the network and may comprise a
site assessment of the physical security of the organization. A network security audit fixes an
organization security flaws in the network and makes it difficult for perpetrators to attack the
network (Network Security Threats 2011).
Since network threats come in a variety of forms and cannot be totally eliminated, it is advisable
that secure updated data backups should be kept on systems that are detached from the network.
None of these strategies will singly eliminate the threats arising from a network connection,
but when they are used together, they can be exceedingly effectual at keeping a network safe.
Besides, well –thought-out organizational policies can be effective at preventing unauthorized
access to critical and parts of the network.
Introduction to Computer Networks
An elementary comprehension of computer networks is essential in order to understand the
codes of network security. A network is any set of interconnected lines, basing this definition
on the current topic, a computer network is basically a set of linked computers. Networks
enable users to share resources and information, and are classified base on a variety of protocols
(Network Security Threats 2011).For instance, a classification based on the connection manner
focuses on the hardware and software systems used to link the individual computer units, such
as optical fiber, wireless connection, or coaxial cable communication. Networks can also be
categorized on scale, this gives Local Area Network (LAN), wide area Network, virtual Private
Network (VPN), among others (Stallings 2010).
Networks are made up of ‘nodes’, which are the individual computers in the network, and at
least one server and/or ‘host’ computers. The nodes are linked together by communication
systems, which may be private, such as that within an institution, or can be accessed by the
public, such as the internet. Several private networks also use the internet.
The moment a computer network is instituted, it immediately becomes vulnerable to network
security threats such as viruses and bugs that may affect the normal functioning of a computer.
Besides, the personal information such as usernames, passwords, credit card numbers and other
critical information may be at risk if the computer does not have adequate security measures.
There are very many threats in a network, some of which are so severe and can bring down a
large network consisting of thousands of computers.
Virus
In the domain of computer networks, a virus refers to a computer program that can replicate
itself, similar to the biological virus. A computer virus spreads from one computer to another
through an executable program that attaches itself on programs, files and folders.
It can spread through various means, for example, if one computer in a network becomes
‘infected’ with a virus, the rest of the computers in the network may become infected too if the
security features are inadequate.
It can also be spread through USB devices, CD, DVD, or portable had drives. A computer virus
may also spread by mailing a web address link to all addresses so that when a person clicks on
the message to go the website, the virus enters this new computer.
Certain viruses are less harmful, however, some are very harmful and can infect a computer in
the network through various ways (Simmonds 2004). A virus can corrupt the files or software
in a computer. Others may attack the computer hardware and bring the whole computer down.
Yet, some viruses may allow a person to have partial control of a computer, this allows for
unauthorized access to files and critical information stored in the computer’s hard drive.
Although the Windows platform is by far the most vulnerable, other operating systems can also
be attacked by viruses.
Network threats arising from viruses can be managed through various ways, however, the most
common technique is to install an antivirus software. UNIX-based systems such as Mac OS
and Linux are far more secure than Windows. Some anti-virus programs can scan file contents
and even zipped folders while some can also scan sent and received mails, a practice known as
‘on-access scanning’ (Simmonds 2004).Vulnerability to viruses can also be reduced by
carrying out data backups regularly on storage media that are not connected to the network or
computer. Security patches availed by software manufacturers can also assist in reducing
attacks by viruses. Secondary storage media must be scanned before opening in the host
computer.
Malware
Malware, short form of malicious software, is a program created to interrupt normal computer
operations or deny a user network or computer resources, gain partial control of the computer,
access files stored in the computer, gather network-based information such as passwords, and
other cruel or dishonest behavior (Curtin 1997).
Malware consists of a large number of malicious programs that includes viruses, Trojans
horses, worms, spyware, false adware, rootkits and other malicious programs. In 2009,
malware was listed as the second most dangerous threat to computer networks. Today, millions
of malware are created daily to exploit networks with weak security features.
Threats arising from malware can be removed using antivirus programs. Most antivirus have
an added feature of removing various malwares from the network of individual PCs. Besides,
anti-spyware software can be used to prevent spyware threats.
Denial-of-Service Attacks
A Denial-of-Service (DoS) attack is a practice aimed at making network resources unavailable
to some users. This vice entails the resolute efforts of a person or group of persons to prevent
an internet site or service functioning normally or bringing it down altogether. This network
threat is commonly committed against websites or services hosted on high profile internet
servers such as financial institutions and credit card payment services (Stallings 2010).
One mode of attack involves flooding a web server with requests in such a way that it cannot
respond to legitimate communication requests, or responds in a sluggish manner that virtually
renders it unusable. In general, DoS attacks are executed by either compelling the targeted
systems to reset, or using up its resources so that it is unable to offer the intended services.
DoS attacks are perhaps the most malicious and hardest to prevent or manage. They are the
most malicious due to the ease with which they can be launched and the difficulty of tracing
their origins, and it is difficult to deny the requests of the attacker without also blocking out
genuine requests for service.
DoS attacks can be prevented through various ways. The first technique is to use firewalls.
Firewalls have simple instructions of blocking or allowing certain IP addresses, or ports,
however, firewall are not very effective in some DoS attacks as they cannot distinguish
legitimate traffic from DoS traffic. Switches and routers can also be used to prevent these
attacks (Kizza 2006). Intrusion-prevention systems (IPS) have been successfully used to halt
DoS attacks that have signatures attached to them.
Unauthorized Access
This is a very wide terminology as it can refer to various types of attacks, however, the objective
of these attacks is to access some information that the computer or server is not supposed to
reveal. Unauthorized access to a computer or server can be achieved by using viruses, malware
and other malicious programs.
This form of threat can be waded off by using antivirus programs and security patches. Another
strategy used by intruders to access a computer on a network is a technique known as packet
sniffers. Packet sniffers can be used on a vulnerable network and they just ‘listen’ on the server
for words such as password or login in the packet stream, then sends the information thereafter
to the perpetrator.
This way, an intruder is able to obtain usernames, passwords, credit card information and other
critical information from unsuspecting users (Bragg et al 2010). This type of threat can be
prevented by using clear-text passwords, besides, data encryption can help divert such attacks.
When using a wireless network, it is advisable that one should use a long or complicated
password, also, it is advisable that the strongest security supported by the wireless connection
hardware should be used, such as encryption tools. Passwords can also be changed regularly.
General Methods for Preventing Network Attacks and Reducing Vulnerability on
Networks
The most commonly used technique for reducing network threats is the installation of antivirus
programs. These programs must be regularly updated and security patches and updates
installed. Improving the security of the network infrastructure can also involve switching on
features that enhance network security on switches, routers, and other hardware (Fadia 2006).
These security features ensure a secure connection, enhance perimeter security, prevents
intrusion, protects identity services, and general security management. Fixing intrusion
detection systems and firewalls offers protection for most areas of the network and allows for
a safe connection. Working on a virtual private network (VPN) can also enhance security. VPNs
provide network access control and encryption services.
Network security can also be improved by undertaking regular network security audits. A
network security audit simply means that an expert comes and examines the security of the
network, he also checks for loopholes that may be used attack the system and fixes them.
The audit can go beyond an inspection of the computers in the network and may comprise a
site assessment of the physical security of the organization. A network security audit fixes an
organization security flaws in the network and makes it difficult for perpetrators to attack the
network (Network Security Threats 2011).
Since network threats come in a variety of forms and cannot be totally eliminated, it is advisable
that secure updated data backups should be kept on systems that are detached from the network.
None of these strategies will singly eliminate the threats arising from a network connection,
but when they are used together, they can be exceedingly effectual at keeping a network safe.
Besides, well –thought-out organizational policies can be effective at preventing unauthorized
access to critical and parts of the network.
Introduction to Computer Networks
An elementary comprehension of computer networks is essential in order to understand the
codes of network security. A network is any set of interconnected lines, basing this definition
on the current topic, a computer network is basically a set of linked computers. Networks
enable users to share resources and information, and are classified base on a variety of protocols
(Network Security Threats 2011).For instance, a classification based on the connection manner
focuses on the hardware and software systems used to link the individual computer units, such
as optical fiber, wireless connection, or coaxial cable communication. Networks can also be
categorized on scale, this gives Local Area Network (LAN), wide area Network, virtual Private
Network (VPN), among others (Stallings 2010).
Networks are made up of ‘nodes’, which are the individual computers in the network, and at
least one server and/or ‘host’ computers. The nodes are linked together by communication
systems, which may be private, such as that within an institution, or can be accessed by the
public, such as the internet. Several private networks also use the internet.
The moment a computer network is instituted, it immediately becomes vulnerable to network
security threats such as viruses and bugs that may affect the normal functioning of a computer.
Besides, the personal information such as usernames, passwords, credit card numbers and other
critical information may be at risk if the computer does not have adequate security measures.
There are very many threats in a network, some of which are so severe and can bring down a
large network consisting of thousands of computers.
Virus
In the domain of computer networks, a virus refers to a computer program that can replicate
itself, similar to the biological virus. A computer virus spreads from one computer to another
through an executable program that attaches itself on programs, files and folders.
It can spread through various means, for example, if one computer in a network becomes
‘infected’ with a virus, the rest of the computers in the network may become infected too if the
security features are inadequate.
It can also be spread through USB devices, CD, DVD, or portable had drives. A computer virus
may also spread by mailing a web address link to all addresses so that when a person clicks on
the message to go the website, the virus enters this new computer.
Certain viruses are less harmful, however, some are very harmful and can infect a computer in
the network through various ways (Simmonds 2004). A virus can corrupt the files or software
in a computer. Others may attack the computer hardware and bring the whole computer down.
Yet, some viruses may allow a person to have partial control of a computer, this allows for
unauthorized access to files and critical information stored in the computer’s hard drive.
Although the Windows platform is by far the most vulnerable, other operating systems can also
be attacked by viruses.
Network threats arising from viruses can be managed through various ways, however, the most
common technique is to install an antivirus software. UNIX-based systems such as Mac OS
and Linux are far more secure than Windows. Some anti-virus programs can scan file contents
and even zipped folders while some can also scan sent and received mails, a practice known as
‘on-access scanning’ (Simmonds 2004).Vulnerability to viruses can also be reduced by
carrying out data backups regularly on storage media that are not connected to the network or
computer. Security patches availed by software manufacturers can also assist in reducing
attacks by viruses. Secondary storage media must be scanned before opening in the host
computer.
Malware
Malware, short form of malicious software, is a program created to interrupt normal computer
operations or deny a user network or computer resources, gain partial control of the computer,
access files stored in the computer, gather network-based information such as passwords, and
other cruel or dishonest behavior (Curtin 1997).
Malware consists of a large number of malicious programs that includes viruses, Trojans
horses, worms, spyware, false adware, rootkits and other malicious programs. In 2009,
malware was listed as the second most dangerous threat to computer networks. Today, millions
of malware are created daily to exploit networks with weak security features.
Threats arising from malware can be removed using antivirus programs. Most antivirus have
an added feature of removing various malwares from the network of individual PCs. Besides,
anti-spyware software can be used to prevent spyware threats.
Denial-of-Service Attacks
A Denial-of-Service (DoS) attack is a practice aimed at making network resources unavailable
to some users. This vice entails the resolute efforts of a person or group of persons to prevent
an internet site or service functioning normally or bringing it down altogether. This network
threat is commonly committed against websites or services hosted on high profile internet
servers such as financial institutions and credit card payment services (Stallings 2010).
One mode of attack involves flooding a web server with requests in such a way that it cannot
respond to legitimate communication requests, or responds in a sluggish manner that virtually
renders it unusable. In general, DoS attacks are executed by either compelling the targeted
systems to reset, or using up its resources so that it is unable to offer the intended services.
DoS attacks are perhaps the most malicious and hardest to prevent or manage. They are the
most malicious due to the ease with which they can be launched and the difficulty of tracing
their origins, and it is difficult to deny the requests of the attacker without also blocking out
genuine requests for service.
DoS attacks can be prevented through various ways. The first technique is to use firewalls.
Firewalls have simple instructions of blocking or allowing certain IP addresses, or ports,
however, firewall are not very effective in some DoS attacks as they cannot distinguish
legitimate traffic from DoS traffic. Switches and routers can also be used to prevent these
attacks (Kizza 2006). Intrusion-prevention systems (IPS) have been successfully used to halt
DoS attacks that have signatures attached to them.
Unauthorized Access
This is a very wide terminology as it can refer to various types of attacks, however, the objective
of these attacks is to access some information that the computer or server is not supposed to
reveal. Unauthorized access to a computer or server can be achieved by using viruses, malware
and other malicious programs.
This form of threat can be waded off by using antivirus programs and security patches. Another
strategy used by intruders to access a computer on a network is a technique known as packet
sniffers. Packet sniffers can be used on a vulnerable network and they just ‘listen’ on the server
for words such as password or login in the packet stream, then sends the information thereafter
to the perpetrator.
This way, an intruder is able to obtain usernames, passwords, credit card information and other
critical information from unsuspecting users (Bragg et al 2010). This type of threat can be
prevented by using clear-text passwords, besides, data encryption can help divert such attacks.
When using a wireless network, it is advisable that one should use a long or complicated
password, also, it is advisable that the strongest security supported by the wireless connection
hardware should be used, such as encryption tools. Passwords can also be changed regularly.
General Methods for Preventing Network Attacks and Reducing Vulnerability on
Networks
The most commonly used technique for reducing network threats is the installation of antivirus
programs. These programs must be regularly updated and security patches and updates
installed. Improving the security of the network infrastructure can also involve switching on
features that enhance network security on switches, routers, and other hardware (Fadia 2006).
These security features ensure a secure connection, enhance perimeter security, prevents
intrusion, protects identity services, and general security management. Fixing intrusion
detection systems and firewalls offers protection for most areas of the network and allows for
a safe connection. Working on a virtual private network (VPN) can also enhance security. VPNs
provide network access control and encryption services.
Network security can also be improved by undertaking regular network security audits. A
network security audit simply means that an expert comes and examines the security of the
network, he also checks for loopholes that may be used attack the system and fixes them.
The audit can go beyond an inspection of the computers in the network and may comprise a
site assessment of the physical security of the organization. A network security audit fixes an
organization security flaws in the network and makes it difficult for perpetrators to attack the
network (Network Security Threats 2011).
Since network threats come in a variety of forms and cannot be totally eliminated, it is advisable
that secure updated data backups should be kept on systems that are detached from the network.
None of these strategies will singly eliminate the threats arising from a network connection,
but when they are used together, they can be exceedingly effectual at keeping a network safe.
Besides, well –thought-out organizational policies can be effective at preventing unauthorized
access to critical and parts of the network.
Introduction to Computer Networks
An elementary comprehension of computer networks is essential in order to understand the
codes of network security. A network is any set of interconnected lines, basing this definition
on the current topic, a computer network is basically a set of linked computers. Networks
enable users to share resources and information, and are classified base on a variety of protocols
(Network Security Threats 2011).For instance, a classification based on the connection manner
focuses on the hardware and software systems used to link the individual computer units, such
as optical fiber, wireless connection, or coaxial cable communication. Networks can also be
categorized on scale, this gives Local Area Network (LAN), wide area Network, virtual Private
Network (VPN), among others (Stallings 2010).
Networks are made up of ‘nodes’, which are the individual computers in the network, and at
least one server and/or ‘host’ computers. The nodes are linked together by communication
systems, which may be private, such as that within an institution, or can be accessed by the
public, such as the internet. Several private networks also use the internet.
The moment a computer network is instituted, it immediately becomes vulnerable to network
security threats such as viruses and bugs that may affect the normal functioning of a computer.
Besides, the personal information such as usernames, passwords, credit card numbers and other
critical information may be at risk if the computer does not have adequate security measures.
There are very many threats in a network, some of which are so severe and can bring down a
large network consisting of thousands of computers.
Virus
In the domain of computer networks, a virus refers to a computer program that can replicate
itself, similar to the biological virus. A computer virus spreads from one computer to another
through an executable program that attaches itself on programs, files and folders.
It can spread through various means, for example, if one computer in a network becomes
‘infected’ with a virus, the rest of the computers in the network may become infected too if the
security features are inadequate.
It can also be spread through USB devices, CD, DVD, or portable had drives. A computer virus
may also spread by mailing a web address link to all addresses so that when a person clicks on
the message to go the website, the virus enters this new computer.
Certain viruses are less harmful, however, some are very harmful and can infect a computer in
the network through various ways (Simmonds 2004). A virus can corrupt the files or software
in a computer. Others may attack the computer hardware and bring the whole computer down.
Yet, some viruses may allow a person to have partial control of a computer, this allows for
unauthorized access to files and critical information stored in the computer’s hard drive.
Although the Windows platform is by far the most vulnerable, other operating systems can also
be attacked by viruses.
Network threats arising from viruses can be managed through various ways, however, the most
common technique is to install an antivirus software. UNIX-based systems such as Mac OS
and Linux are far more secure than Windows. Some anti-virus programs can scan file contents
and even zipped folders while some can also scan sent and received mails, a practice known as
‘on-access scanning’ (Simmonds 2004).Vulnerability to viruses can also be reduced by
carrying out data backups regularly on storage media that are not connected to the network or
computer. Security patches availed by software manufacturers can also assist in reducing
attacks by viruses. Secondary storage media must be scanned before opening in the host
computer.
Malware
Malware, short form of malicious software, is a program created to interrupt normal computer
operations or deny a user network or computer resources, gain partial control of the computer,
access files stored in the computer, gather network-based information such as passwords, and
other cruel or dishonest behavior (Curtin 1997).
Malware consists of a large number of malicious programs that includes viruses, Trojans
horses, worms, spyware, false adware, rootkits and other malicious programs. In 2009,
malware was listed as the second most dangerous threat to computer networks. Today, millions
of malware are created daily to exploit networks with weak security features.
Threats arising from malware can be removed using antivirus programs. Most antivirus have
an added feature of removing various malwares from the network of individual PCs. Besides,
anti-spyware software can be used to prevent spyware threats.
Denial-of-Service Attacks
A Denial-of-Service (DoS) attack is a practice aimed at making network resources unavailable
to some users. This vice entails the resolute efforts of a person or group of persons to prevent
an internet site or service functioning normally or bringing it down altogether. This network
threat is commonly committed against websites or services hosted on high profile internet
servers such as financial institutions and credit card payment services (Stallings 2010).
One mode of attack involves flooding a web server with requests in such a way that it cannot
respond to legitimate communication requests, or responds in a sluggish manner that virtually
renders it unusable. In general, DoS attacks are executed by either compelling the targeted
systems to reset, or using up its resources so that it is unable to offer the intended services.
DoS attacks are perhaps the most malicious and hardest to prevent or manage. They are the
most malicious due to the ease with which they can be launched and the difficulty of tracing
their origins, and it is difficult to deny the requests of the attacker without also blocking out
genuine requests for service.
DoS attacks can be prevented through various ways. The first technique is to use firewalls.
Firewalls have simple instructions of blocking or allowing certain IP addresses, or ports,
however, firewall are not very effective in some DoS attacks as they cannot distinguish
legitimate traffic from DoS traffic. Switches and routers can also be used to prevent these
attacks (Kizza 2006). Intrusion-prevention systems (IPS) have been successfully used to halt
DoS attacks that have signatures attached to them.
Unauthorized Access
This is a very wide terminology as it can refer to various types of attacks, however, the objective
of these attacks is to access some information that the computer or server is not supposed to
reveal. Unauthorized access to a computer or server can be achieved by using viruses, malware
and other malicious programs.
This form of threat can be waded off by using antivirus programs and security patches. Another
strategy used by intruders to access a computer on a network is a technique known as packet
sniffers. Packet sniffers can be used on a vulnerable network and they just ‘listen’ on the server
for words such as password or login in the packet stream, then sends the information thereafter
to the perpetrator.
This way, an intruder is able to obtain usernames, passwords, credit card information and other
critical information from unsuspecting users (Bragg et al 2010). This type of threat can be
prevented by using clear-text passwords, besides, data encryption can help divert such attacks.
When using a wireless network, it is advisable that one should use a long or complicated
password, also, it is advisable that the strongest security supported by the wireless connection
hardware should be used, such as encryption tools. Passwords can also be changed regularly.
General Methods for Preventing Network Attacks and Reducing Vulnerability on
Networks
The most commonly used technique for reducing network threats is the installation of antivirus
programs. These programs must be regularly updated and security patches and updates
installed. Improving the security of the network infrastructure can also involve switching on
features that enhance network security on switches, routers, and other hardware (Fadia 2006).
These security features ensure a secure connection, enhance perimeter security, prevents
intrusion, protects identity services, and general security management. Fixing intrusion
detection systems and firewalls offers protection for most areas of the network and allows for
a safe connection. Working on a virtual private network (VPN) can also enhance security. VPNs
provide network access control and encryption services.
Network security can also be improved by undertaking regular network security audits. A
network security audit simply means that an expert comes and examines the security of the
network, he also checks for loopholes that may be used attack the system and fixes them.
The audit can go beyond an inspection of the computers in the network and may comprise a
site assessment of the physical security of the organization. A network security audit fixes an
organization security flaws in the network and makes it difficult for perpetrators to attack the
network (Network Security Threats 2011).
Since network threats come in a variety of forms and cannot be totally eliminated, it is advisable
that secure updated data backups should be kept on systems that are detached from the network.
None of these strategies will singly eliminate the threats arising from a network connection,
but when they are used together, they can be exceedingly effectual at keeping a network safe.
Besides, well –thought-out organizational policies can be effective at preventing unauthorized
access to critical and parts of the network.
Introduction to Computer Networks
An elementary comprehension of computer networks is essential in order to understand the
codes of network security. A network is any set of interconnected lines, basing this definition
on the current topic, a computer network is basically a set of linked computers. Networks
enable users to share resources and information, and are classified base on a variety of protocols
(Network Security Threats 2011).For instance, a classification based on the connection manner
focuses on the hardware and software systems used to link the individual computer units, such
as optical fiber, wireless connection, or coaxial cable communication. Networks can also be
categorized on scale, this gives Local Area Network (LAN), wide area Network, virtual Private
Network (VPN), among others (Stallings 2010).
Networks are made up of ‘nodes’, which are the individual computers in the network, and at
least one server and/or ‘host’ computers. The nodes are linked together by communication
systems, which may be private, such as that within an institution, or can be accessed by the
public, such as the internet. Several private networks also use the internet.
The moment a computer network is instituted, it immediately becomes vulnerable to network
security threats such as viruses and bugs that may affect the normal functioning of a computer.
Besides, the personal information such as usernames, passwords, credit card numbers and other
critical information may be at risk if the computer does not have adequate security measures.
There are very many threats in a network, some of which are so severe and can bring down a
large network consisting of thousands of computers.
Virus
In the domain of computer networks, a virus refers to a computer program that can replicate
itself, similar to the biological virus. A computer virus spreads from one computer to another
through an executable program that attaches itself on programs, files and folders.
It can spread through various means, for example, if one computer in a network becomes
‘infected’ with a virus, the rest of the computers in the network may become infected too if the
security features are inadequate.
It can also be spread through USB devices, CD, DVD, or portable had drives. A computer virus
may also spread by mailing a web address link to all addresses so that when a person clicks on
the message to go the website, the virus enters this new computer.
Certain viruses are less harmful, however, some are very harmful and can infect a computer in
the network through various ways (Simmonds 2004). A virus can corrupt the files or software
in a computer. Others may attack the computer hardware and bring the whole computer down.
Yet, some viruses may allow a person to have partial control of a computer, this allows for
unauthorized access to files and critical information stored in the computer’s hard drive.
Although the Windows platform is by far the most vulnerable, other operating systems can also
be attacked by viruses.
Network threats arising from viruses can be managed through various ways, however, the most
common technique is to install an antivirus software. UNIX-based systems such as Mac OS
and Linux are far more secure than Windows. Some anti-virus programs can scan file contents
and even zipped folders while some can also scan sent and received mails, a practice known as
‘on-access scanning’ (Simmonds 2004).Vulnerability to viruses can also be reduced by
carrying out data backups regularly on storage media that are not connected to the network or
computer. Security patches availed by software manufacturers can also assist in reducing
attacks by viruses. Secondary storage media must be scanned before opening in the host
computer.
Malware
Malware, short form of malicious software, is a program created to interrupt normal computer
operations or deny a user network or computer resources, gain partial control of the computer,
access files stored in the computer, gather network-based information such as passwords, and
other cruel or dishonest behavior (Curtin 1997).
Malware consists of a large number of malicious programs that includes viruses, Trojans
horses, worms, spyware, false adware, rootkits and other malicious programs. In 2009,
malware was listed as the second most dangerous threat to computer networks. Today, millions
of malware are created daily to exploit networks with weak security features.
Threats arising from malware can be removed using antivirus programs. Most antivirus have
an added feature of removing various malwares from the network of individual PCs. Besides,
anti-spyware software can be used to prevent spyware threats.
Denial-of-Service Attacks
A Denial-of-Service (DoS) attack is a practice aimed at making network resources unavailable
to some users. This vice entails the resolute efforts of a person or group of persons to prevent
an internet site or service functioning normally or bringing it down altogether. This network
threat is commonly committed against websites or services hosted on high profile internet
servers such as financial institutions and credit card payment services (Stallings 2010).
One mode of attack involves flooding a web server with requests in such a way that it cannot
respond to legitimate communication requests, or responds in a sluggish manner that virtually
renders it unusable. In general, DoS attacks are executed by either compelling the targeted
systems to reset, or using up its resources so that it is unable to offer the intended services.
DoS attacks are perhaps the most malicious and hardest to prevent or manage. They are the
most malicious due to the ease with which they can be launched and the difficulty of tracing
their origins, and it is difficult to deny the requests of the attacker without also blocking out
genuine requests for service.
DoS attacks can be prevented through various ways. The first technique is to use firewalls.
Firewalls have simple instructions of blocking or allowing certain IP addresses, or ports,
however, firewall are not very effective in some DoS attacks as they cannot distinguish
legitimate traffic from DoS traffic. Switches and routers can also be used to prevent these
attacks (Kizza 2006). Intrusion-prevention systems (IPS) have been successfully used to halt
DoS attacks that have signatures attached to them.
Unauthorized Access
This is a very wide terminology as it can refer to various types of attacks, however, the objective
of these attacks is to access some information that the computer or server is not supposed to
reveal. Unauthorized access to a computer or server can be achieved by using viruses, malware
and other malicious programs.
This form of threat can be waded off by using antivirus programs and security patches. Another
strategy used by intruders to access a computer on a network is a technique known as packet
sniffers. Packet sniffers can be used on a vulnerable network and they just ‘listen’ on the server
for words such as password or login in the packet stream, then sends the information thereafter
to the perpetrator.
This way, an intruder is able to obtain usernames, passwords, credit card information and other
critical information from unsuspecting users (Bragg et al 2010). This type of threat can be
prevented by using clear-text passwords, besides, data encryption can help divert such attacks.
When using a wireless network, it is advisable that one should use a long or complicated
password, also, it is advisable that the strongest security supported by the wireless connection
hardware should be used, such as encryption tools. Passwords can also be changed regularly.
General Methods for Preventing Network Attacks and Reducing Vulnerability on
Networks
The most commonly used technique for reducing network threats is the installation of antivirus
programs. These programs must be regularly updated and security patches and updates
installed. Improving the security of the network infrastructure can also involve switching on
features that enhance network security on switches, routers, and other hardware (Fadia 2006).
These security features ensure a secure connection, enhance perimeter security, prevents
intrusion, protects identity services, and general security management. Fixing intrusion
detection systems and firewalls offers protection for most areas of the network and allows for
a safe connection. Working on a virtual private network (VPN) can also enhance security. VPNs
provide network access control and encryption services.
Network security can also be improved by undertaking regular network security audits. A
network security audit simply means that an expert comes and examines the security of the
network, he also checks for loopholes that may be used attack the system and fixes them.
The audit can go beyond an inspection of the computers in the network and may comprise a
site assessment of the physical security of the organization. A network security audit fixes an
organization security flaws in the network and makes it difficult for perpetrators to attack the
network (Network Security Threats 2011).
Since network threats come in a variety of forms and cannot be totally eliminated, it is advisable
that secure updated data backups should be kept on systems that are detached from the network.
None of these strategies will singly eliminate the threats arising from a network connection,
but when they are used together, they can be exceedingly effectual at keeping a network safe.
Besides, well –thought-out organizational policies can be effective at preventing unauthorized
access to critical and parts of the network.
Introduction to Computer Networks
An elementary comprehension of computer networks is essential in order to understand the
codes of network security. A network is any set of interconnected lines, basing this definition
on the current topic, a computer network is basically a set of linked computers. Networks
enable users to share resources and information, and are classified base on a variety of protocols
(Network Security Threats 2011).For instance, a classification based on the connection manner
focuses on the hardware and software systems used to link the individual computer units, such
as optical fiber, wireless connection, or coaxial cable communication. Networks can also be
categorized on scale, this gives Local Area Network (LAN), wide area Network, virtual Private
Network (VPN), among others (Stallings 2010).
Networks are made up of ‘nodes’, which are the individual computers in the network, and at
least one server and/or ‘host’ computers. The nodes are linked together by communication
systems, which may be private, such as that within an institution, or can be accessed by the
public, such as the internet. Several private networks also use the internet.
The moment a computer network is instituted, it immediately becomes vulnerable to network
security threats such as viruses and bugs that may affect the normal functioning of a computer.
Besides, the personal information such as usernames, passwords, credit card numbers and other
critical information may be at risk if the computer does not have adequate security measures.
There are very many threats in a network, some of which are so severe and can bring down a
large network consisting of thousands of computers.
Virus
In the domain of computer networks, a virus refers to a computer program that can replicate
itself, similar to the biological virus. A computer virus spreads from one computer to another
through an executable program that attaches itself on programs, files and folders.
It can spread through various means, for example, if one computer in a network becomes
‘infected’ with a virus, the rest of the computers in the network may become infected too if the
security features are inadequate.
It can also be spread through USB devices, CD, DVD, or portable had drives. A computer virus
may also spread by mailing a web address link to all addresses so that when a person clicks on
the message to go the website, the virus enters this new computer.
Certain viruses are less harmful, however, some are very harmful and can infect a computer in
the network through various ways (Simmonds 2004). A virus can corrupt the files or software
in a computer. Others may attack the computer hardware and bring the whole computer down.
Yet, some viruses may allow a person to have partial control of a computer, this allows for
unauthorized access to files and critical information stored in the computer’s hard drive.
Although the Windows platform is by far the most vulnerable, other operating systems can also
be attacked by viruses.
Network threats arising from viruses can be managed through various ways, however, the most
common technique is to install an antivirus software. UNIX-based systems such as Mac OS
and Linux are far more secure than Windows. Some anti-virus programs can scan file contents
and even zipped folders while some can also scan sent and received mails, a practice known as
‘on-access scanning’ (Simmonds 2004).Vulnerability to viruses can also be reduced by
carrying out data backups regularly on storage media that are not connected to the network or
computer. Security patches availed by software manufacturers can also assist in reducing
attacks by viruses. Secondary storage media must be scanned before opening in the host
computer.
Malware
Malware, short form of malicious software, is a program created to interrupt normal computer
operations or deny a user network or computer resources, gain partial control of the computer,
access files stored in the computer, gather network-based information such as passwords, and
other cruel or dishonest behavior (Curtin 1997).
Malware consists of a large number of malicious programs that includes viruses, Trojans
horses, worms, spyware, false adware, rootkits and other malicious programs. In 2009,
malware was listed as the second most dangerous threat to computer networks. Today, millions
of malware are created daily to exploit networks with weak security features.
Threats arising from malware can be removed using antivirus programs. Most antivirus have
an added feature of removing various malwares from the network of individual PCs. Besides,
anti-spyware software can be used to prevent spyware threats.
Denial-of-Service Attacks
A Denial-of-Service (DoS) attack is a practice aimed at making network resources unavailable
to some users. This vice entails the resolute efforts of a person or group of persons to prevent
an internet site or service functioning normally or bringing it down altogether. This network
threat is commonly committed against websites or services hosted on high profile internet
servers such as financial institutions and credit card payment services (Stallings 2010).
One mode of attack involves flooding a web server with requests in such a way that it cannot
respond to legitimate communication requests, or responds in a sluggish manner that virtually
renders it unusable. In general, DoS attacks are executed by either compelling the targeted
systems to reset, or using up its resources so that it is unable to offer the intended services.
DoS attacks are perhaps the most malicious and hardest to prevent or manage. They are the
most malicious due to the ease with which they can be launched and the difficulty of tracing
their origins, and it is difficult to deny the requests of the attacker without also blocking out
genuine requests for service.
DoS attacks can be prevented through various ways. The first technique is to use firewalls.
Firewalls have simple instructions of blocking or allowing certain IP addresses, or ports,
however, firewall are not very effective in some DoS attacks as they cannot distinguish
legitimate traffic from DoS traffic. Switches and routers can also be used to prevent these
attacks (Kizza 2006). Intrusion-prevention systems (IPS) have been successfully used to halt
DoS attacks that have signatures attached to them.
Unauthorized Access
This is a very wide terminology as it can refer to various types of attacks, however, the objective
of these attacks is to access some information that the computer or server is not supposed to
reveal. Unauthorized access to a computer or server can be achieved by using viruses, malware
and other malicious programs.
This form of threat can be waded off by using antivirus programs and security patches. Another
strategy used by intruders to access a computer on a network is a technique known as packet
sniffers. Packet sniffers can be used on a vulnerable network and they just ‘listen’ on the server
for words such as password or login in the packet stream, then sends the information thereafter
to the perpetrator.
This way, an intruder is able to obtain usernames, passwords, credit card information and other
critical information from unsuspecting users (Bragg et al 2010). This type of threat can be
prevented by using clear-text passwords, besides, data encryption can help divert such attacks.
When using a wireless network, it is advisable that one should use a long or complicated
password, also, it is advisable that the strongest security supported by the wireless connection
hardware should be used, such as encryption tools. Passwords can also be changed regularly.
General Methods for Preventing Network Attacks and Reducing Vulnerability on
Networks
The most commonly used technique for reducing network threats is the installation of antivirus
programs. These programs must be regularly updated and security patches and updates
installed. Improving the security of the network infrastructure can also involve switching on
features that enhance network security on switches, routers, and other hardware (Fadia 2006).
These security features ensure a secure connection, enhance perimeter security, prevents
intrusion, protects identity services, and general security management. Fixing intrusion
detection systems and firewalls offers protection for most areas of the network and allows for
a safe connection. Working on a virtual private network (VPN) can also enhance security. VPNs
provide network access control and encryption services.
Network security can also be improved by undertaking regular network security audits. A
network security audit simply means that an expert comes and examines the security of the
network, he also checks for loopholes that may be used attack the system and fixes them.
The audit can go beyond an inspection of the computers in the network and may comprise a
site assessment of the physical security of the organization. A network security audit fixes an
organization security flaws in the network and makes it difficult for perpetrators to attack the
network (Network Security Threats 2011).
Since network threats come in a variety of forms and cannot be totally eliminated, it is advisable
that secure updated data backups should be kept on systems that are detached from the network.
None of these strategies will singly eliminate the threats arising from a network connection,
but when they are used together, they can be exceedingly effectual at keeping a network safe.
Besides, well –thought-out organizational policies can be effective at preventing unauthorized
access to critical and parts of the network.
Introduction to Computer Networks
An elementary comprehension of computer networks is essential in order to understand the
codes of network security. A network is any set of interconnected lines, basing this definition
on the current topic, a computer network is basically a set of linked computers. Networks
enable users to share resources and information, and are classified base on a variety of protocols
(Network Security Threats 2011).For instance, a classification based on the connection manner
focuses on the hardware and software systems used to link the individual computer units, such
as optical fiber, wireless connection, or coaxial cable communication. Networks can also be
categorized on scale, this gives Local Area Network (LAN), wide area Network, virtual Private
Network (VPN), among others (Stallings 2010).
Networks are made up of ‘nodes’, which are the individual computers in the network, and at
least one server and/or ‘host’ computers. The nodes are linked together by communication
systems, which may be private, such as that within an institution, or can be accessed by the
public, such as the internet. Several private networks also use the internet.
The moment a computer network is instituted, it immediately becomes vulnerable to network
security threats such as viruses and bugs that may affect the normal functioning of a computer.
Besides, the personal information such as usernames, passwords, credit card numbers and other
critical information may be at risk if the computer does not have adequate security measures.
There are very many threats in a network, some of which are so severe and can bring down a
large network consisting of thousands of computers.
Virus
In the domain of computer networks, a virus refers to a computer program that can replicate
itself, similar to the biological virus. A computer virus spreads from one computer to another
through an executable program that attaches itself on programs, files and folders.
It can spread through various means, for example, if one computer in a network becomes
‘infected’ with a virus, the rest of the computers in the network may become infected too if the
security features are inadequate.
It can also be spread through USB devices, CD, DVD, or portable had drives. A computer virus
may also spread by mailing a web address link to all addresses so that when a person clicks on
the message to go the website, the virus enters this new computer.
Certain viruses are less harmful, however, some are very harmful and can infect a computer in
the network through various ways (Simmonds 2004). A virus can corrupt the files or software
in a computer. Others may attack the computer hardware and bring the whole computer down.
Yet, some viruses may allow a person to have partial control of a computer, this allows for
unauthorized access to files and critical information stored in the computer’s hard drive.
Although the Windows platform is by far the most vulnerable, other operating systems can also
be attacked by viruses.
Network threats arising from viruses can be managed through various ways, however, the most
common technique is to install an antivirus software. UNIX-based systems such as Mac OS
and Linux are far more secure than Windows. Some anti-virus programs can scan file contents
and even zipped folders while some can also scan sent and received mails, a practice known as
‘on-access scanning’ (Simmonds 2004).Vulnerability to viruses can also be reduced by
carrying out data backups regularly on storage media that are not connected to the network or
computer. Security patches availed by software manufacturers can also assist in reducing
attacks by viruses. Secondary storage media must be scanned before opening in the host
computer.
Malware
Malware, short form of malicious software, is a program created to interrupt normal computer
operations or deny a user network or computer resources, gain partial control of the computer,
access files stored in the computer, gather network-based information such as passwords, and
other cruel or dishonest behavior (Curtin 1997).
Malware consists of a large number of malicious programs that includes viruses, Trojans
horses, worms, spyware, false adware, rootkits and other malicious programs. In 2009,
malware was listed as the second most dangerous threat to computer networks. Today, millions
of malware are created daily to exploit networks with weak security features.
Threats arising from malware can be removed using antivirus programs. Most antivirus have
an added feature of removing various malwares from the network of individual PCs. Besides,
anti-spyware software can be used to prevent spyware threats.
Denial-of-Service Attacks
A Denial-of-Service (DoS) attack is a practice aimed at making network resources unavailable
to some users. This vice entails the resolute efforts of a person or group of persons to prevent
an internet site or service functioning normally or bringing it down altogether. This network
threat is commonly committed against websites or services hosted on high profile internet
servers such as financial institutions and credit card payment services (Stallings 2010).
One mode of attack involves flooding a web server with requests in such a way that it cannot
respond to legitimate communication requests, or responds in a sluggish manner that virtually
renders it unusable. In general, DoS attacks are executed by either compelling the targeted
systems to reset, or using up its resources so that it is unable to offer the intended services.
DoS attacks are perhaps the most malicious and hardest to prevent or manage. They are the
most malicious due to the ease with which they can be launched and the difficulty of tracing
their origins, and it is difficult to deny the requests of the attacker without also blocking out
genuine requests for service.
DoS attacks can be prevented through various ways. The first technique is to use firewalls.
Firewalls have simple instructions of blocking or allowing certain IP addresses, or ports,
however, firewall are not very effective in some DoS attacks as they cannot distinguish
legitimate traffic from DoS traffic. Switches and routers can also be used to prevent these
attacks (Kizza 2006). Intrusion-prevention systems (IPS) have been successfully used to halt
DoS attacks that have signatures attached to them.
Unauthorized Access
This is a very wide terminology as it can refer to various types of attacks, however, the objective
of these attacks is to access some information that the computer or server is not supposed to
reveal. Unauthorized access to a computer or server can be achieved by using viruses, malware
and other malicious programs.
This form of threat can be waded off by using antivirus programs and security patches. Another
strategy used by intruders to access a computer on a network is a technique known as packet
sniffers. Packet sniffers can be used on a vulnerable network and they just ‘listen’ on the server
for words such as password or login in the packet stream, then sends the information thereafter
to the perpetrator.
This way, an intruder is able to obtain usernames, passwords, credit card information and other
critical information from unsuspecting users (Bragg et al 2010). This type of threat can be
prevented by using clear-text passwords, besides, data encryption can help divert such attacks.
When using a wireless network, it is advisable that one should use a long or complicated
password, also, it is advisable that the strongest security supported by the wireless connection
hardware should be used, such as encryption tools. Passwords can also be changed regularly.
General Methods for Preventing Network Attacks and Reducing Vulnerability on
Networks
The most commonly used technique for reducing network threats is the installation of antivirus
programs. These programs must be regularly updated and security patches and updates
installed. Improving the security of the network infrastructure can also involve switching on
features that enhance network security on switches, routers, and other hardware (Fadia 2006).
These security features ensure a secure connection, enhance perimeter security, prevents
intrusion, protects identity services, and general security management. Fixing intrusion
detection systems and firewalls offers protection for most areas of the network and allows for
a safe connection. Working on a virtual private network (VPN) can also enhance security. VPNs
provide network access control and encryption services.
Network security can also be improved by undertaking regular network security audits. A
network security audit simply means that an expert comes and examines the security of the
network, he also checks for loopholes that may be used attack the system and fixes them.
The audit can go beyond an inspection of the computers in the network and may comprise a
site assessment of the physical security of the organization. A network security audit fixes an
organization security flaws in the network and makes it difficult for perpetrators to attack the
network (Network Security Threats 2011).
Since network threats come in a variety of forms and cannot be totally eliminated, it is advisable
that secure updated data backups should be kept on systems that are detached from the network.
None of these strategies will singly eliminate the threats arising from a network connection,
but when they are used together, they can be exceedingly effectual at keeping a network safe.
Besides, well –thought-out organizational policies can be effective at preventing unauthorized
access to critical and parts of the network.
Introduction to Computer Networks
An elementary comprehension of computer networks is essential in order to understand the
codes of network security. A network is any set of interconnected lines, basing this definition
on the current topic, a computer network is basically a set of linked computers. Networks
enable users to share resources and information, and are classified base on a variety of protocols
(Network Security Threats 2011).For instance, a classification based on the connection manner
focuses on the hardware and software systems used to link the individual computer units, such
as optical fiber, wireless connection, or coaxial cable communication. Networks can also be
categorized on scale, this gives Local Area Network (LAN), wide area Network, virtual Private
Network (VPN), among others (Stallings 2010).
Networks are made up of ‘nodes’, which are the individual computers in the network, and at
least one server and/or ‘host’ computers. The nodes are linked together by communication
systems, which may be private, such as that within an institution, or can be accessed by the
public, such as the internet. Several private networks also use the internet.
The moment a computer network is instituted, it immediately becomes vulnerable to network
security threats such as viruses and bugs that may affect the normal functioning of a computer.
Besides, the personal information such as usernames, passwords, credit card numbers and other
critical information may be at risk if the computer does not have adequate security measures.
There are very many threats in a network, some of which are so severe and can bring down a
large network consisting of thousands of computers.
Virus
In the domain of computer networks, a virus refers to a computer program that can replicate
itself, similar to the biological virus. A computer virus spreads from one computer to another
through an executable program that attaches itself on programs, files and folders.
It can spread through various means, for example, if one computer in a network becomes
‘infected’ with a virus, the rest of the computers in the network may become infected too if the
security features are inadequate.
It can also be spread through USB devices, CD, DVD, or portable had drives. A computer virus
may also spread by mailing a web address link to all addresses so that when a person clicks on
the message to go the website, the virus enters this new computer.
Certain viruses are less harmful, however, some are very harmful and can infect a computer in
the network through various ways (Simmonds 2004). A virus can corrupt the files or software
in a computer. Others may attack the computer hardware and bring the whole computer down.
Yet, some viruses may allow a person to have partial control of a computer, this allows for
unauthorized access to files and critical information stored in the computer’s hard drive.
Although the Windows platform is by far the most vulnerable, other operating systems can also
be attacked by viruses.
Network threats arising from viruses can be managed through various ways, however, the most
common technique is to install an antivirus software. UNIX-based systems such as Mac OS
and Linux are far more secure than Windows. Some anti-virus programs can scan file contents
and even zipped folders while some can also scan sent and received mails, a practice known as
‘on-access scanning’ (Simmonds 2004).Vulnerability to viruses can also be reduced by
carrying out data backups regularly on storage media that are not connected to the network or
computer. Security patches availed by software manufacturers can also assist in reducing
attacks by viruses. Secondary storage media must be scanned before opening in the host
computer.
Malware
Malware, short form of malicious software, is a program created to interrupt normal computer
operations or deny a user network or computer resources, gain partial control of the computer,
access files stored in the computer, gather network-based information such as passwords, and
other cruel or dishonest behavior (Curtin 1997).
Malware consists of a large number of malicious programs that includes viruses, Trojans
horses, worms, spyware, false adware, rootkits and other malicious programs. In 2009,
malware was listed as the second most dangerous threat to computer networks. Today, millions
of malware are created daily to exploit networks with weak security features.
Threats arising from malware can be removed using antivirus programs. Most antivirus have
an added feature of removing various malwares from the network of individual PCs. Besides,
anti-spyware software can be used to prevent spyware threats.
Denial-of-Service Attacks
A Denial-of-Service (DoS) attack is a practice aimed at making network resources unavailable
to some users. This vice entails the resolute efforts of a person or group of persons to prevent
an internet site or service functioning normally or bringing it down altogether. This network
threat is commonly committed against websites or services hosted on high profile internet
servers such as financial institutions and credit card payment services (Stallings 2010).
One mode of attack involves flooding a web server with requests in such a way that it cannot
respond to legitimate communication requests, or responds in a sluggish manner that virtually
renders it unusable. In general, DoS attacks are executed by either compelling the targeted
systems to reset, or using up its resources so that it is unable to offer the intended services.
DoS attacks are perhaps the most malicious and hardest to prevent or manage. They are the
most malicious due to the ease with which they can be launched and the difficulty of tracing
their origins, and it is difficult to deny the requests of the attacker without also blocking out
genuine requests for service.
DoS attacks can be prevented through various ways. The first technique is to use firewalls.
Firewalls have simple instructions of blocking or allowing certain IP addresses, or ports,
however, firewall are not very effective in some DoS attacks as they cannot distinguish
legitimate traffic from DoS traffic. Switches and routers can also be used to prevent these
attacks (Kizza 2006). Intrusion-prevention systems (IPS) have been successfully used to halt
DoS attacks that have signatures attached to them.
Unauthorized Access
This is a very wide terminology as it can refer to various types of attacks, however, the objective
of these attacks is to access some information that the computer or server is not supposed to
reveal. Unauthorized access to a computer or server can be achieved by using viruses, malware
and other malicious programs.
This form of threat can be waded off by using antivirus programs and security patches. Another
strategy used by intruders to access a computer on a network is a technique known as packet
sniffers. Packet sniffers can be used on a vulnerable network and they just ‘listen’ on the server
for words such as password or login in the packet stream, then sends the information thereafter
to the perpetrator.
This way, an intruder is able to obtain usernames, passwords, credit card information and other
critical information from unsuspecting users (Bragg et al 2010). This type of threat can be
prevented by using clear-text passwords, besides, data encryption can help divert such attacks.
When using a wireless network, it is advisable that one should use a long or complicated
password, also, it is advisable that the strongest security supported by the wireless connection
hardware should be used, such as encryption tools. Passwords can also be changed regularly.
General Methods for Preventing Network Attacks and Reducing Vulnerability on
Networks
The most commonly used technique for reducing network threats is the installation of antivirus
programs. These programs must be regularly updated and security patches and updates
installed. Improving the security of the network infrastructure can also involve switching on
features that enhance network security on switches, routers, and other hardware (Fadia 2006).
These security features ensure a secure connection, enhance perimeter security, prevents
intrusion, protects identity services, and general security management. Fixing intrusion
detection systems and firewalls offers protection for most areas of the network and allows for
a safe connection. Working on a virtual private network (VPN) can also enhance security. VPNs
provide network access control and encryption services.
Network security can also be improved by undertaking regular network security audits. A
network security audit simply means that an expert comes and examines the security of the
network, he also checks for loopholes that may be used attack the system and fixes them.
The audit can go beyond an inspection of the computers in the network and may comprise a
site assessment of the physical security of the organization. A network security audit fixes an
organization security flaws in the network and makes it difficult for perpetrators to attack the
network (Network Security Threats 2011).
Since network threats come in a variety of forms and cannot be totally eliminated, it is advisable
that secure updated data backups should be kept on systems that are detached from the network.
None of these strategies will singly eliminate the threats arising from a network connection,
but when they are used together, they can be exceedingly effectual at keeping a network safe.
Besides, well –thought-out organizational policies can be effective at preventing unauthorized
access to critical and parts of the network.
Introduction to Computer Networks
An elementary comprehension of computer networks is essential in order to understand the
codes of network security. A network is any set of interconnected lines, basing this definition
on the current topic, a computer network is basically a set of linked computers. Networks
enable users to share resources and information, and are classified base on a variety of protocols
(Network Security Threats 2011).For instance, a classification based on the connection manner
focuses on the hardware and software systems used to link the individual computer units, such
as optical fiber, wireless connection, or coaxial cable communication. Networks can also be
categorized on scale, this gives Local Area Network (LAN), wide area Network, virtual Private
Network (VPN), among others (Stallings 2010).
Networks are made up of ‘nodes’, which are the individual computers in the network, and at
least one server and/or ‘host’ computers. The nodes are linked together by communication
systems, which may be private, such as that within an institution, or can be accessed by the
public, such as the internet. Several private networks also use the internet.
The moment a computer network is instituted, it immediately becomes vulnerable to network
security threats such as viruses and bugs that may affect the normal functioning of a computer.
Besides, the personal information such as usernames, passwords, credit card numbers and other
critical information may be at risk if the computer does not have adequate security measures.
There are very many threats in a network, some of which are so severe and can bring down a
large network consisting of thousands of computers.
Virus
In the domain of computer networks, a virus refers to a computer program that can replicate
itself, similar to the biological virus. A computer virus spreads from one computer to another
through an executable program that attaches itself on programs, files and folders.
It can spread through various means, for example, if one computer in a network becomes
‘infected’ with a virus, the rest of the computers in the network may become infected too if the
security features are inadequate.
It can also be spread through USB devices, CD, DVD, or portable had drives. A computer virus
may also spread by mailing a web address link to all addresses so that when a person clicks on
the message to go the website, the virus enters this new computer.
Certain viruses are less harmful, however, some are very harmful and can infect a computer in
the network through various ways (Simmonds 2004). A virus can corrupt the files or software
in a computer. Others may attack the computer hardware and bring the whole computer down.
Yet, some viruses may allow a person to have partial control of a computer, this allows for
unauthorized access to files and critical information stored in the computer’s hard drive.
Although the Windows platform is by far the most vulnerable, other operating systems can also
be attacked by viruses.
Network threats arising from viruses can be managed through various ways, however, the most
common technique is to install an antivirus software. UNIX-based systems such as Mac OS
and Linux are far more secure than Windows. Some anti-virus programs can scan file contents
and even zipped folders while some can also scan sent and received mails, a practice known as
‘on-access scanning’ (Simmonds 2004).Vulnerability to viruses can also be reduced by
carrying out data backups regularly on storage media that are not connected to the network or
computer. Security patches availed by software manufacturers can also assist in reducing
attacks by viruses. Secondary storage media must be scanned before opening in the host
computer.
Malware
Malware, short form of malicious software, is a program created to interrupt normal computer
operations or deny a user network or computer resources, gain partial control of the computer,
access files stored in the computer, gather network-based information such as passwords, and
other cruel or dishonest behavior (Curtin 1997).
Malware consists of a large number of malicious programs that includes viruses, Trojans
horses, worms, spyware, false adware, rootkits and other malicious programs. In 2009,
malware was listed as the second most dangerous threat to computer networks. Today, millions
of malware are created daily to exploit networks with weak security features.
Threats arising from malware can be removed using antivirus programs. Most antivirus have
an added feature of removing various malwares from the network of individual PCs. Besides,
anti-spyware software can be used to prevent spyware threats.
Denial-of-Service Attacks
A Denial-of-Service (DoS) attack is a practice aimed at making network resources unavailable
to some users. This vice entails the resolute efforts of a person or group of persons to prevent
an internet site or service functioning normally or bringing it down altogether. This network
threat is commonly committed against websites or services hosted on high profile internet
servers such as financial institutions and credit card payment services (Stallings 2010).
One mode of attack involves flooding a web server with requests in such a way that it cannot
respond to legitimate communication requests, or responds in a sluggish manner that virtually
renders it unusable. In general, DoS attacks are executed by either compelling the targeted
systems to reset, or using up its resources so that it is unable to offer the intended services.
DoS attacks are perhaps the most malicious and hardest to prevent or manage. They are the
most malicious due to the ease with which they can be launched and the difficulty of tracing
their origins, and it is difficult to deny the requests of the attacker without also blocking out
genuine requests for service.
DoS attacks can be prevented through various ways. The first technique is to use firewalls.
Firewalls have simple instructions of blocking or allowing certain IP addresses, or ports,
however, firewall are not very effective in some DoS attacks as they cannot distinguish
legitimate traffic from DoS traffic. Switches and routers can also be used to prevent these
attacks (Kizza 2006). Intrusion-prevention systems (IPS) have been successfully used to halt
DoS attacks that have signatures attached to them.
Unauthorized Access
This is a very wide terminology as it can refer to various types of attacks, however, the objective
of these attacks is to access some information that the computer or server is not supposed to
reveal. Unauthorized access to a computer or server can be achieved by using viruses, malware
and other malicious programs.
This form of threat can be waded off by using antivirus programs and security patches. Another
strategy used by intruders to access a computer on a network is a technique known as packet
sniffers. Packet sniffers can be used on a vulnerable network and they just ‘listen’ on the server
for words such as password or login in the packet stream, then sends the information thereafter
to the perpetrator.
This way, an intruder is able to obtain usernames, passwords, credit card information and other
critical information from unsuspecting users (Bragg et al 2010). This type of threat can be
prevented by using clear-text passwords, besides, data encryption can help divert such attacks.
When using a wireless network, it is advisable that one should use a long or complicated
password, also, it is advisable that the strongest security supported by the wireless connection
hardware should be used, such as encryption tools. Passwords can also be changed regularly.
General Methods for Preventing Network Attacks and Reducing Vulnerability on
Networks
The most commonly used technique for reducing network threats is the installation of antivirus
programs. These programs must be regularly updated and security patches and updates
installed. Improving the security of the network infrastructure can also involve switching on
features that enhance network security on switches, routers, and other hardware (Fadia 2006).
These security features ensure a secure connection, enhance perimeter security, prevents
intrusion, protects identity services, and general security management. Fixing intrusion
detection systems and firewalls offers protection for most areas of the network and allows for
a safe connection. Working on a virtual private network (VPN) can also enhance security. VPNs
provide network access control and encryption services.
Network security can also be improved by undertaking regular network security audits. A
network security audit simply means that an expert comes and examines the security of the
network, he also checks for loopholes that may be used attack the system and fixes them.
The audit can go beyond an inspection of the computers in the network and may comprise a
site assessment of the physical security of the organization. A network security audit fixes an
organization security flaws in the network and makes it difficult for perpetrators to attack the
network (Network Security Threats 2011).
Since network threats come in a variety of forms and cannot be totally eliminated, it is advisable
that secure updated data backups should be kept on systems that are detached from the network.
None of these strategies will singly eliminate the threats arising from a network connection,
but when they are used together, they can be exceedingly effectual at keeping a network safe.
Besides, well –thought-out organizational policies can be effective at preventing unauthorized
access to critical and parts of the network.
Introduction to Computer Networks
An elementary comprehension of computer networks is essential in order to understand the
codes of network security. A network is any set of interconnected lines, basing this definition
on the current topic, a computer network is basically a set of linked computers. Networks
enable users to share resources and information, and are classified base on a variety of protocols
(Network Security Threats 2011).For instance, a classification based on the connection manner
focuses on the hardware and software systems used to link the individual computer units, such
as optical fiber, wireless connection, or coaxial cable communication. Networks can also be
categorized on scale, this gives Local Area Network (LAN), wide area Network, virtual Private
Network (VPN), among others (Stallings 2010).
Networks are made up of ‘nodes’, which are the individual computers in the network, and at
least one server and/or ‘host’ computers. The nodes are linked together by communication
systems, which may be private, such as that within an institution, or can be accessed by the
public, such as the internet. Several private networks also use the internet.
The moment a computer network is instituted, it immediately becomes vulnerable to network
security threats such as viruses and bugs that may affect the normal functioning of a computer.
Besides, the personal information such as usernames, passwords, credit card numbers and other
critical information may be at risk if the computer does not have adequate security measures.
There are very many threats in a network, some of which are so severe and can bring down a
large network consisting of thousands of computers.
Virus
In the domain of computer networks, a virus refers to a computer program that can replicate
itself, similar to the biological virus. A computer virus spreads from one computer to another
through an executable program that attaches itself on programs, files and folders.
It can spread through various means, for example, if one computer in a network becomes
‘infected’ with a virus, the rest of the computers in the network may become infected too if the
security features are inadequate.
It can also be spread through USB devices, CD, DVD, or portable had drives. A computer virus
may also spread by mailing a web address link to all addresses so that when a person clicks on
the message to go the website, the virus enters this new computer.
Certain viruses are less harmful, however, some are very harmful and can infect a computer in
the network through various ways (Simmonds 2004). A virus can corrupt the files or software
in a computer. Others may attack the computer hardware and bring the whole computer down.
Yet, some viruses may allow a person to have partial control of a computer, this allows for
unauthorized access to files and critical information stored in the computer’s hard drive.
Although the Windows platform is by far the most vulnerable, other operating systems can also
be attacked by viruses.
Network threats arising from viruses can be managed through various ways, however, the most
common technique is to install an antivirus software. UNIX-based systems such as Mac OS
and Linux are far more secure than Windows. Some anti-virus programs can scan file contents
and even zipped folders while some can also scan sent and received mails, a practice known as
‘on-access scanning’ (Simmonds 2004).Vulnerability to viruses can also be reduced by
carrying out data backups regularly on storage media that are not connected to the network or
computer. Security patches availed by software manufacturers can also assist in reducing
attacks by viruses. Secondary storage media must be scanned before opening in the host
computer.
Malware
Malware, short form of malicious software, is a program created to interrupt normal computer
operations or deny a user network or computer resources, gain partial control of the computer,
access files stored in the computer, gather network-based information such as passwords, and
other cruel or dishonest behavior (Curtin 1997).
Malware consists of a large number of malicious programs that includes viruses, Trojans
horses, worms, spyware, false adware, rootkits and other malicious programs. In 2009,
malware was listed as the second most dangerous threat to computer networks. Today, millions
of malware are created daily to exploit networks with weak security features.
Threats arising from malware can be removed using antivirus programs. Most antivirus have
an added feature of removing various malwares from the network of individual PCs. Besides,
anti-spyware software can be used to prevent spyware threats.
Denial-of-Service Attacks
A Denial-of-Service (DoS) attack is a practice aimed at making network resources unavailable
to some users. This vice entails the resolute efforts of a person or group of persons to prevent
an internet site or service functioning normally or bringing it down altogether. This network
threat is commonly committed against websites or services hosted on high profile internet
servers such as financial institutions and credit card payment services (Stallings 2010).
One mode of attack involves flooding a web server with requests in such a way that it cannot
respond to legitimate communication requests, or responds in a sluggish manner that virtually
renders it unusable. In general, DoS attacks are executed by either compelling the targeted
systems to reset, or using up its resources so that it is unable to offer the intended services.
DoS attacks are perhaps the most malicious and hardest to prevent or manage. They are the
most malicious due to the ease with which they can be launched and the difficulty of tracing
their origins, and it is difficult to deny the requests of the attacker without also blocking out
genuine requests for service.
DoS attacks can be prevented through various ways. The first technique is to use firewalls.
Firewalls have simple instructions of blocking or allowing certain IP addresses, or ports,
however, firewall are not very effective in some DoS attacks as they cannot distinguish
legitimate traffic from DoS traffic. Switches and routers can also be used to prevent these
attacks (Kizza 2006). Intrusion-prevention systems (IPS) have been successfully used to halt
DoS attacks that have signatures attached to them.
Unauthorized Access
This is a very wide terminology as it can refer to various types of attacks, however, the objective
of these attacks is to access some information that the computer or server is not supposed to
reveal. Unauthorized access to a computer or server can be achieved by using viruses, malware
and other malicious programs.
This form of threat can be waded off by using antivirus programs and security patches. Another
strategy used by intruders to access a computer on a network is a technique known as packet
sniffers. Packet sniffers can be used on a vulnerable network and they just ‘listen’ on the server
for words such as password or login in the packet stream, then sends the information thereafter
to the perpetrator.
This way, an intruder is able to obtain usernames, passwords, credit card information and other
critical information from unsuspecting users (Bragg et al 2010). This type of threat can be
prevented by using clear-text passwords, besides, data encryption can help divert such attacks.
When using a wireless network, it is advisable that one should use a long or complicated
password, also, it is advisable that the strongest security supported by the wireless connection
hardware should be used, such as encryption tools. Passwords can also be changed regularly.
General Methods for Preventing Network Attacks and Reducing Vulnerability on
Networks
The most commonly used technique for reducing network threats is the installation of antivirus
programs. These programs must be regularly updated and security patches and updates
installed. Improving the security of the network infrastructure can also involve switching on
features that enhance network security on switches, routers, and other hardware (Fadia 2006).
These security features ensure a secure connection, enhance perimeter security, prevents
intrusion, protects identity services, and general security management. Fixing intrusion
detection systems and firewalls offers protection for most areas of the network and allows for
a safe connection. Working on a virtual private network (VPN) can also enhance security. VPNs
provide network access control and encryption services.
Network security can also be improved by undertaking regular network security audits. A
network security audit simply means that an expert comes and examines the security of the
network, he also checks for loopholes that may be used attack the system and fixes them.
The audit can go beyond an inspection of the computers in the network and may comprise a
site assessment of the physical security of the organization. A network security audit fixes an
organization security flaws in the network and makes it difficult for perpetrators to attack the
network (Network Security Threats 2011).
Since network threats come in a variety of forms and cannot be totally eliminated, it is advisable
that secure updated data backups should be kept on systems that are detached from the network.
None of these strategies will singly eliminate the threats arising from a network connection,
but when they are used together, they can be exceedingly effectual at keeping a network safe.
Besides, well –thought-out organizational policies can be effective at preventing unauthorized
access to critical and parts of the network.
Introduction to Computer Networks
An elementary comprehension of computer networks is essential in order to understand the
codes of network security. A network is any set of interconnected lines, basing this definition
on the current topic, a computer network is basically a set of linked computers. Networks
enable users to share resources and information, and are classified base on a variety of protocols
(Network Security Threats 2011).For instance, a classification based on the connection manner
focuses on the hardware and software systems used to link the individual computer units, such
as optical fiber, wireless connection, or coaxial cable communication. Networks can also be
categorized on scale, this gives Local Area Network (LAN), wide area Network, virtual Private
Network (VPN), among others (Stallings 2010).
Networks are made up of ‘nodes’, which are the individual computers in the network, and at
least one server and/or ‘host’ computers. The nodes are linked together by communication
systems, which may be private, such as that within an institution, or can be accessed by the
public, such as the internet. Several private networks also use the internet.
The moment a computer network is instituted, it immediately becomes vulnerable to network
security threats such as viruses and bugs that may affect the normal functioning of a computer.
Besides, the personal information such as usernames, passwords, credit card numbers and other
critical information may be at risk if the computer does not have adequate security measures.
There are very many threats in a network, some of which are so severe and can bring down a
large network consisting of thousands of computers.
Virus
In the domain of computer networks, a virus refers to a computer program that can replicate
itself, similar to the biological virus. A computer virus spreads from one computer to another
through an executable program that attaches itself on programs, files and folders.
It can spread through various means, for example, if one computer in a network becomes
‘infected’ with a virus, the rest of the computers in the network may become infected too if the
security features are inadequate.
It can also be spread through USB devices, CD, DVD, or portable had drives. A computer virus
may also spread by mailing a web address link to all addresses so that when a person clicks on
the message to go the website, the virus enters this new computer.
Certain viruses are less harmful, however, some are very harmful and can infect a computer in
the network through various ways (Simmonds 2004). A virus can corrupt the files or software
in a computer. Others may attack the computer hardware and bring the whole computer down.
Yet, some viruses may allow a person to have partial control of a computer, this allows for
unauthorized access to files and critical information stored in the computer’s hard drive.
Although the Windows platform is by far the most vulnerable, other operating systems can also
be attacked by viruses.
Network threats arising from viruses can be managed through various ways, however, the most
common technique is to install an antivirus software. UNIX-based systems such as Mac OS
and Linux are far more secure than Windows. Some anti-virus programs can scan file contents
and even zipped folders while some can also scan sent and received mails, a practice known as
‘on-access scanning’ (Simmonds 2004).Vulnerability to viruses can also be reduced by
carrying out data backups regularly on storage media that are not connected to the network or
computer. Security patches availed by software manufacturers can also assist in reducing
attacks by viruses. Secondary storage media must be scanned before opening in the host
computer.
Malware
Malware, short form of malicious software, is a program created to interrupt normal computer
operations or deny a user network or computer resources, gain partial control of the computer,
access files stored in the computer, gather network-based information such as passwords, and
other cruel or dishonest behavior (Curtin 1997).
Malware consists of a large number of malicious programs that includes viruses, Trojans
horses, worms, spyware, false adware, rootkits and other malicious programs. In 2009,
malware was listed as the second most dangerous threat to computer networks. Today, millions
of malware are created daily to exploit networks with weak security features.
Threats arising from malware can be removed using antivirus programs. Most antivirus have
an added feature of removing various malwares from the network of individual PCs. Besides,
anti-spyware software can be used to prevent spyware threats.
Denial-of-Service Attacks
A Denial-of-Service (DoS) attack is a practice aimed at making network resources unavailable
to some users. This vice entails the resolute efforts of a person or group of persons to prevent
an internet site or service functioning normally or bringing it down altogether. This network
threat is commonly committed against websites or services hosted on high profile internet
servers such as financial institutions and credit card payment services (Stallings 2010).
One mode of attack involves flooding a web server with requests in such a way that it cannot
respond to legitimate communication requests, or responds in a sluggish manner that virtually
renders it unusable. In general, DoS attacks are executed by either compelling the targeted
systems to reset, or using up its resources so that it is unable to offer the intended services.
DoS attacks are perhaps the most malicious and hardest to prevent or manage. They are the
most malicious due to the ease with which they can be launched and the difficulty of tracing
their origins, and it is difficult to deny the requests of the attacker without also blocking out
genuine requests for service.
DoS attacks can be prevented through various ways. The first technique is to use firewalls.
Firewalls have simple instructions of blocking or allowing certain IP addresses, or ports,
however, firewall are not very effective in some DoS attacks as they cannot distinguish
legitimate traffic from DoS traffic. Switches and routers can also be used to prevent these
attacks (Kizza 2006). Intrusion-prevention systems (IPS) have been successfully used to halt
DoS attacks that have signatures attached to them.
Unauthorized Access
This is a very wide terminology as it can refer to various types of attacks, however, the objective
of these attacks is to access some information that the computer or server is not supposed to
reveal. Unauthorized access to a computer or server can be achieved by using viruses, malware
and other malicious programs.
This form of threat can be waded off by using antivirus programs and security patches. Another
strategy used by intruders to access a computer on a network is a technique known as packet
sniffers. Packet sniffers can be used on a vulnerable network and they just ‘listen’ on the server
for words such as password or login in the packet stream, then sends the information thereafter
to the perpetrator.
This way, an intruder is able to obtain usernames, passwords, credit card information and other
critical information from unsuspecting users (Bragg et al 2010). This type of threat can be
prevented by using clear-text passwords, besides, data encryption can help divert such attacks.
When using a wireless network, it is advisable that one should use a long or complicated
password, also, it is advisable that the strongest security supported by the wireless connection
hardware should be used, such as encryption tools. Passwords can also be changed regularly.
General Methods for Preventing Network Attacks and Reducing Vulnerability on
Networks
The most commonly used technique for reducing network threats is the installation of antivirus
programs. These programs must be regularly updated and security patches and updates
installed. Improving the security of the network infrastructure can also involve switching on
features that enhance network security on switches, routers, and other hardware (Fadia 2006).
These security features ensure a secure connection, enhance perimeter security, prevents
intrusion, protects identity services, and general security management. Fixing intrusion
detection systems and firewalls offers protection for most areas of the network and allows for
a safe connection. Working on a virtual private network (VPN) can also enhance security. VPNs
provide network access control and encryption services.
Network security can also be improved by undertaking regular network security audits. A
network security audit simply means that an expert comes and examines the security of the
network, he also checks for loopholes that may be used attack the system and fixes them.
The audit can go beyond an inspection of the computers in the network and may comprise a
site assessment of the physical security of the organization. A network security audit fixes an
organization security flaws in the network and makes it difficult for perpetrators to attack the
network (Network Security Threats 2011).
Since network threats come in a variety of forms and cannot be totally eliminated, it is advisable
that secure updated data backups should be kept on systems that are detached from the network.
None of these strategies will singly eliminate the threats arising from a network connection,
but when they are used together, they can be exceedingly effectual at keeping a network safe.
Besides, well –thought-out organizational policies can be effective at preventing unauthorized
access to critical and parts of the network.
Introduction to Computer Networks
An elementary comprehension of computer networks is essential in order to understand the
codes of network security. A network is any set of interconnected lines, basing this definition
on the current topic, a computer network is basically a set of linked computers. Networks
enable users to share resources and information, and are classified base on a variety of protocols
(Network Security Threats 2011).For instance, a classification based on the connection manner
focuses on the hardware and software systems used to link the individual computer units, such
as optical fiber, wireless connection, or coaxial cable communication. Networks can also be
categorized on scale, this gives Local Area Network (LAN), wide area Network, virtual Private
Network (VPN), among others (Stallings 2010).
Networks are made up of ‘nodes’, which are the individual computers in the network, and at
least one server and/or ‘host’ computers. The nodes are linked together by communication
systems, which may be private, such as that within an institution, or can be accessed by the
public, such as the internet. Several private networks also use the internet.
The moment a computer network is instituted, it immediately becomes vulnerable to network
security threats such as viruses and bugs that may affect the normal functioning of a computer.
Besides, the personal information such as usernames, passwords, credit card numbers and other
critical information may be at risk if the computer does not have adequate security measures.
There are very many threats in a network, some of which are so severe and can bring down a
large network consisting of thousands of computers.
Virus
In the domain of computer networks, a virus refers to a computer program that can replicate
itself, similar to the biological virus. A computer virus spreads from one computer to another
through an executable program that attaches itself on programs, files and folders.
It can spread through various means, for example, if one computer in a network becomes
‘infected’ with a virus, the rest of the computers in the network may become infected too if the
security features are inadequate.
It can also be spread through USB devices, CD, DVD, or portable had drives. A computer virus
may also spread by mailing a web address link to all addresses so that when a person clicks on
the message to go the website, the virus enters this new computer.
Certain viruses are less harmful, however, some are very harmful and can infect a computer in
the network through various ways (Simmonds 2004). A virus can corrupt the files or software
in a computer. Others may attack the computer hardware and bring the whole computer down.
Yet, some viruses may allow a person to have partial control of a computer, this allows for
unauthorized access to files and critical information stored in the computer’s hard drive.
Although the Windows platform is by far the most vulnerable, other operating systems can also
be attacked by viruses.
Network threats arising from viruses can be managed through various ways, however, the most
common technique is to install an antivirus software. UNIX-based systems such as Mac OS
and Linux are far more secure than Windows. Some anti-virus programs can scan file contents
and even zipped folders while some can also scan sent and received mails, a practice known as
‘on-access scanning’ (Simmonds 2004).Vulnerability to viruses can also be reduced by
carrying out data backups regularly on storage media that are not connected to the network or
computer. Security patches availed by software manufacturers can also assist in reducing
attacks by viruses. Secondary storage media must be scanned before opening in the host
computer.
Malware
Malware, short form of malicious software, is a program created to interrupt normal computer
operations or deny a user network or computer resources, gain partial control of the computer,
access files stored in the computer, gather network-based information such as passwords, and
other cruel or dishonest behavior (Curtin 1997).
Malware consists of a large number of malicious programs that includes viruses, Trojans
horses, worms, spyware, false adware, rootkits and other malicious programs. In 2009,
malware was listed as the second most dangerous threat to computer networks. Today, millions
of malware are created daily to exploit networks with weak security features.
Threats arising from malware can be removed using antivirus programs. Most antivirus have
an added feature of removing various malwares from the network of individual PCs. Besides,
anti-spyware software can be used to prevent spyware threats.
Denial-of-Service Attacks
A Denial-of-Service (DoS) attack is a practice aimed at making network resources unavailable
to some users. This vice entails the resolute efforts of a person or group of persons to prevent
an internet site or service functioning normally or bringing it down altogether. This network
threat is commonly committed against websites or services hosted on high profile internet
servers such as financial institutions and credit card payment services (Stallings 2010).
One mode of attack involves flooding a web server with requests in such a way that it cannot
respond to legitimate communication requests, or responds in a sluggish manner that virtually
renders it unusable. In general, DoS attacks are executed by either compelling the targeted
systems to reset, or using up its resources so that it is unable to offer the intended services.
DoS attacks are perhaps the most malicious and hardest to prevent or manage. They are the
most malicious due to the ease with which they can be launched and the difficulty of tracing
their origins, and it is difficult to deny the requests of the attacker without also blocking out
genuine requests for service.
DoS attacks can be prevented through various ways. The first technique is to use firewalls.
Firewalls have simple instructions of blocking or allowing certain IP addresses, or ports,
however, firewall are not very effective in some DoS attacks as they cannot distinguish
legitimate traffic from DoS traffic. Switches and routers can also be used to prevent these
attacks (Kizza 2006). Intrusion-prevention systems (IPS) have been successfully used to halt
DoS attacks that have signatures attached to them.
Unauthorized Access
This is a very wide terminology as it can refer to various types of attacks, however, the objective
of these attacks is to access some information that the computer or server is not supposed to
reveal. Unauthorized access to a computer or server can be achieved by using viruses, malware
and other malicious programs.
This form of threat can be waded off by using antivirus programs and security patches. Another
strategy used by intruders to access a computer on a network is a technique known as packet
sniffers. Packet sniffers can be used on a vulnerable network and they just ‘listen’ on the server
for words such as password or login in the packet stream, then sends the information thereafter
to the perpetrator.
This way, an intruder is able to obtain usernames, passwords, credit card information and other
critical information from unsuspecting users (Bragg et al 2010). This type of threat can be
prevented by using clear-text passwords, besides, data encryption can help divert such attacks.
When using a wireless network, it is advisable that one should use a long or complicated
password, also, it is advisable that the strongest security supported by the wireless connection
hardware should be used, such as encryption tools. Passwords can also be changed regularly.
General Methods for Preventing Network Attacks and Reducing Vulnerability on
Networks
The most commonly used technique for reducing network threats is the installation of antivirus
programs. These programs must be regularly updated and security patches and updates
installed. Improving the security of the network infrastructure can also involve switching on
features that enhance network security on switches, routers, and other hardware (Fadia 2006).
These security features ensure a secure connection, enhance perimeter security, prevents
intrusion, protects identity services, and general security management. Fixing intrusion
detection systems and firewalls offers protection for most areas of the network and allows for
a safe connection. Working on a virtual private network (VPN) can also enhance security. VPNs
provide network access control and encryption services.
Network security can also be improved by undertaking regular network security audits. A
network security audit simply means that an expert comes and examines the security of the
network, he also checks for loopholes that may be used attack the system and fixes them.
The audit can go beyond an inspection of the computers in the network and may comprise a
site assessment of the physical security of the organization. A network security audit fixes an
organization security flaws in the network and makes it difficult for perpetrators to attack the
network (Network Security Threats 2011).
Since network threats come in a variety of forms and cannot be totally eliminated, it is advisable
that secure updated data backups should be kept on systems that are detached from the network.
None of these strategies will singly eliminate the threats arising from a network connection,
but when they are used together, they can be exceedingly effectual at keeping a network safe.
Besides, well –thought-out organizational policies can be effective at preventing unauthorized
access to critical and parts of the network.
Introduction to Computer Networks
An elementary comprehension of computer networks is essential in order to understand the
codes of network security. A network is any set of interconnected lines, basing this definition
on the current topic, a computer network is basically a set of linked computers. Networks
enable users to share resources and information, and are classified base on a variety of protocols
(Network Security Threats 2011).For instance, a classification based on the connection manner
focuses on the hardware and software systems used to link the individual computer units, such
as optical fiber, wireless connection, or coaxial cable communication. Networks can also be
categorized on scale, this gives Local Area Network (LAN), wide area Network, virtual Private
Network (VPN), among others (Stallings 2010).
Networks are made up of ‘nodes’, which are the individual computers in the network, and at
least one server and/or ‘host’ computers. The nodes are linked together by communication
systems, which may be private, such as that within an institution, or can be accessed by the
public, such as the internet. Several private networks also use the internet.
The moment a computer network is instituted, it immediately becomes vulnerable to network
security threats such as viruses and bugs that may affect the normal functioning of a computer.
Besides, the personal information such as usernames, passwords, credit card numbers and other
critical information may be at risk if the computer does not have adequate security measures.
There are very many threats in a network, some of which are so severe and can bring down a
large network consisting of thousands of computers.
Virus
In the domain of computer networks, a virus refers to a computer program that can replicate
itself, similar to the biological virus. A computer virus spreads from one computer to another
through an executable program that attaches itself on programs, files and folders.
It can spread through various means, for example, if one computer in a network becomes
‘infected’ with a virus, the rest of the computers in the network may become infected too if the
security features are inadequate.
It can also be spread through USB devices, CD, DVD, or portable had drives. A computer virus
may also spread by mailing a web address link to all addresses so that when a person clicks on
the message to go the website, the virus enters this new computer.
Certain viruses are less harmful, however, some are very harmful and can infect a computer in
the network through various ways (Simmonds 2004). A virus can corrupt the files or software
in a computer. Others may attack the computer hardware and bring the whole computer down.
Yet, some viruses may allow a person to have partial control of a computer, this allows for
unauthorized access to files and critical information stored in the computer’s hard drive.
Although the Windows platform is by far the most vulnerable, other operating systems can also
be attacked by viruses.
Network threats arising from viruses can be managed through various ways, however, the most
common technique is to install an antivirus software. UNIX-based systems such as Mac OS
and Linux are far more secure than Windows. Some anti-virus programs can scan file contents
and even zipped folders while some can also scan sent and received mails, a practice known as
‘on-access scanning’ (Simmonds 2004).Vulnerability to viruses can also be reduced by
carrying out data backups regularly on storage media that are not connected to the network or
computer. Security patches availed by software manufacturers can also assist in reducing
attacks by viruses. Secondary storage media must be scanned before opening in the host
computer.
Malware
Malware, short form of malicious software, is a program created to interrupt normal computer
operations or deny a user network or computer resources, gain partial control of the computer,
access files stored in the computer, gather network-based information such as passwords, and
other cruel or dishonest behavior (Curtin 1997).
Malware consists of a large number of malicious programs that includes viruses, Trojans
horses, worms, spyware, false adware, rootkits and other malicious programs. In 2009,
malware was listed as the second most dangerous threat to computer networks. Today, millions
of malware are created daily to exploit networks with weak security features.
Threats arising from malware can be removed using antivirus programs. Most antivirus have
an added feature of removing various malwares from the network of individual PCs. Besides,
anti-spyware software can be used to prevent spyware threats.
Denial-of-Service Attacks
A Denial-of-Service (DoS) attack is a practice aimed at making network resources unavailable
to some users. This vice entails the resolute efforts of a person or group of persons to prevent
an internet site or service functioning normally or bringing it down altogether. This network
threat is commonly committed against websites or services hosted on high profile internet
servers such as financial institutions and credit card payment services (Stallings 2010).
One mode of attack involves flooding a web server with requests in such a way that it cannot
respond to legitimate communication requests, or responds in a sluggish manner that virtually
renders it unusable. In general, DoS attacks are executed by either compelling the targeted
systems to reset, or using up its resources so that it is unable to offer the intended services.
DoS attacks are perhaps the most malicious and hardest to prevent or manage. They are the
most malicious due to the ease with which they can be launched and the difficulty of tracing
their origins, and it is difficult to deny the requests of the attacker without also blocking out
genuine requests for service.
DoS attacks can be prevented through various ways. The first technique is to use firewalls.
Firewalls have simple instructions of blocking or allowing certain IP addresses, or ports,
however, firewall are not very effective in some DoS attacks as they cannot distinguish
legitimate traffic from DoS traffic. Switches and routers can also be used to prevent these
attacks (Kizza 2006). Intrusion-prevention systems (IPS) have been successfully used to halt
DoS attacks that have signatures attached to them.
Unauthorized Access
This is a very wide terminology as it can refer to various types of attacks, however, the objective
of these attacks is to access some information that the computer or server is not supposed to
reveal. Unauthorized access to a computer or server can be achieved by using viruses, malware
and other malicious programs.
This form of threat can be waded off by using antivirus programs and security patches. Another
strategy used by intruders to access a computer on a network is a technique known as packet
sniffers. Packet sniffers can be used on a vulnerable network and they just ‘listen’ on the server
for words such as password or login in the packet stream, then sends the information thereafter
to the perpetrator.
This way, an intruder is able to obtain usernames, passwords, credit card information and other
critical information from unsuspecting users (Bragg et al 2010). This type of threat can be
prevented by using clear-text passwords, besides, data encryption can help divert such attacks.
When using a wireless network, it is advisable that one should use a long or complicated
password, also, it is advisable that the strongest security supported by the wireless connection
hardware should be used, such as encryption tools. Passwords can also be changed regularly.
General Methods for Preventing Network Attacks and Reducing Vulnerability on
Networks
The most commonly used technique for reducing network threats is the installation of antivirus
programs. These programs must be regularly updated and security patches and updates
installed. Improving the security of the network infrastructure can also involve switching on
features that enhance network security on switches, routers, and other hardware (Fadia 2006).
These security features ensure a secure connection, enhance perimeter security, prevents
intrusion, protects identity services, and general security management. Fixing intrusion
detection systems and firewalls offers protection for most areas of the network and allows for
a safe connection. Working on a virtual private network (VPN) can also enhance security. VPNs
provide network access control and encryption services.
Network security can also be improved by undertaking regular network security audits. A
network security audit simply means that an expert comes and examines the security of the
network, he also checks for loopholes that may be used attack the system and fixes them.
The audit can go beyond an inspection of the computers in the network and may comprise a
site assessment of the physical security of the organization. A network security audit fixes an
organization security flaws in the network and makes it difficult for perpetrators to attack the
network (Network Security Threats 2011).
Since network threats come in a variety of forms and cannot be totally eliminated, it is advisable
that secure updated data backups should be kept on systems that are detached from the network.
None of these strategies will singly eliminate the threats arising from a network connection,
but when they are used together, they can be exceedingly effectual at keeping a network safe.
Besides, well –thought-out organizational policies can be effective at preventing unauthorized
access to critical and parts of the network.
Introduction to Computer Networks
An elementary comprehension of computer networks is essential in order to understand the
codes of network security. A network is any set of interconnected lines, basing this definition
on the current topic, a computer network is basically a set of linked computers. Networks
enable users to share resources and information, and are classified base on a variety of protocols
(Network Security Threats 2011).For instance, a classification based on the connection manner
focuses on the hardware and software systems used to link the individual computer units, such
as optical fiber, wireless connection, or coaxial cable communication. Networks can also be
categorized on scale, this gives Local Area Network (LAN), wide area Network, virtual Private
Network (VPN), among others (Stallings 2010).
Networks are made up of ‘nodes’, which are the individual computers in the network, and at
least one server and/or ‘host’ computers. The nodes are linked together by communication
systems, which may be private, such as that within an institution, or can be accessed by the
public, such as the internet. Several private networks also use the internet.
The moment a computer network is instituted, it immediately becomes vulnerable to network
security threats such as viruses and bugs that may affect the normal functioning of a computer.
Besides, the personal information such as usernames, passwords, credit card numbers and other
critical information may be at risk if the computer does not have adequate security measures.
There are very many threats in a network, some of which are so severe and can bring down a
large network consisting of thousands of computers.
Virus
In the domain of computer networks, a virus refers to a computer program that can replicate
itself, similar to the biological virus. A computer virus spreads from one computer to another
through an executable program that attaches itself on programs, files and folders.
It can spread through various means, for example, if one computer in a network becomes
‘infected’ with a virus, the rest of the computers in the network may become infected too if the
security features are inadequate.
It can also be spread through USB devices, CD, DVD, or portable had drives. A computer virus
may also spread by mailing a web address link to all addresses so that when a person clicks on
the message to go the website, the virus enters this new computer.
Certain viruses are less harmful, however, some are very harmful and can infect a computer in
the network through various ways (Simmonds 2004). A virus can corrupt the files or software
in a computer. Others may attack the computer hardware and bring the whole computer down.
Yet, some viruses may allow a person to have partial control of a computer, this allows for
unauthorized access to files and critical information stored in the computer’s hard drive.
Although the Windows platform is by far the most vulnerable, other operating systems can also
be attacked by viruses.
Network threats arising from viruses can be managed through various ways, however, the most
common technique is to install an antivirus software. UNIX-based systems such as Mac OS
and Linux are far more secure than Windows. Some anti-virus programs can scan file contents
and even zipped folders while some can also scan sent and received mails, a practice known as
‘on-access scanning’ (Simmonds 2004).Vulnerability to viruses can also be reduced by
carrying out data backups regularly on storage media that are not connected to the network or
computer. Security patches availed by software manufacturers can also assist in reducing
attacks by viruses. Secondary storage media must be scanned before opening in the host
computer.
Malware
Malware, short form of malicious software, is a program created to interrupt normal computer
operations or deny a user network or computer resources, gain partial control of the computer,
access files stored in the computer, gather network-based information such as passwords, and
other cruel or dishonest behavior (Curtin 1997).
Malware consists of a large number of malicious programs that includes viruses, Trojans
horses, worms, spyware, false adware, rootkits and other malicious programs. In 2009,
malware was listed as the second most dangerous threat to computer networks. Today, millions
of malware are created daily to exploit networks with weak security features.
Threats arising from malware can be removed using antivirus programs. Most antivirus have
an added feature of removing various malwares from the network of individual PCs. Besides,
anti-spyware software can be used to prevent spyware threats.
Denial-of-Service Attacks
A Denial-of-Service (DoS) attack is a practice aimed at making network resources unavailable
to some users. This vice entails the resolute efforts of a person or group of persons to prevent
an internet site or service functioning normally or bringing it down altogether. This network
threat is commonly committed against websites or services hosted on high profile internet
servers such as financial institutions and credit card payment services (Stallings 2010).
One mode of attack involves flooding a web server with requests in such a way that it cannot
respond to legitimate communication requests, or responds in a sluggish manner that virtually
renders it unusable. In general, DoS attacks are executed by either compelling the targeted
systems to reset, or using up its resources so that it is unable to offer the intended services.
DoS attacks are perhaps the most malicious and hardest to prevent or manage. They are the
most malicious due to the ease with which they can be launched and the difficulty of tracing
their origins, and it is difficult to deny the requests of the attacker without also blocking out
genuine requests for service.
DoS attacks can be prevented through various ways. The first technique is to use firewalls.
Firewalls have simple instructions of blocking or allowing certain IP addresses, or ports,
however, firewall are not very effective in some DoS attacks as they cannot distinguish
legitimate traffic from DoS traffic. Switches and routers can also be used to prevent these
attacks (Kizza 2006). Intrusion-prevention systems (IPS) have been successfully used to halt
DoS attacks that have signatures attached to them.
Unauthorized Access
This is a very wide terminology as it can refer to various types of attacks, however, the objective
of these attacks is to access some information that the computer or server is not supposed to
reveal. Unauthorized access to a computer or server can be achieved by using viruses, malware
and other malicious programs.
This form of threat can be waded off by using antivirus programs and security patches. Another
strategy used by intruders to access a computer on a network is a technique known as packet
sniffers. Packet sniffers can be used on a vulnerable network and they just ‘listen’ on the server
for words such as password or login in the packet stream, then sends the information thereafter
to the perpetrator.
This way, an intruder is able to obtain usernames, passwords, credit card information and other
critical information from unsuspecting users (Bragg et al 2010). This type of threat can be
prevented by using clear-text passwords, besides, data encryption can help divert such attacks.
When using a wireless network, it is advisable that one should use a long or complicated
password, also, it is advisable that the strongest security supported by the wireless connection
hardware should be used, such as encryption tools. Passwords can also be changed regularly.
General Methods for Preventing Network Attacks and Reducing Vulnerability on
Networks
The most commonly used technique for reducing network threats is the installation of antivirus
programs. These programs must be regularly updated and security patches and updates
installed. Improving the security of the network infrastructure can also involve switching on
features that enhance network security on switches, routers, and other hardware (Fadia 2006).
These security features ensure a secure connection, enhance perimeter security, prevents
intrusion, protects identity services, and general security management. Fixing intrusion
detection systems and firewalls offers protection for most areas of the network and allows for
a safe connection. Working on a virtual private network (VPN) can also enhance security. VPNs
provide network access control and encryption services.
Network security can also be improved by undertaking regular network security audits. A
network security audit simply means that an expert comes and examines the security of the
network, he also checks for loopholes that may be used attack the system and fixes them.
The audit can go beyond an inspection of the computers in the network and may comprise a
site assessment of the physical security of the organization. A network security audit fixes an
organization security flaws in the network and makes it difficult for perpetrators to attack the
network (Network Security Threats 2011).
Since network threats come in a variety of forms and cannot be totally eliminated, it is advisable
that secure updated data backups should be kept on systems that are detached from the network.
None of these strategies will singly eliminate the threats arising from a network connection,
but when they are used together, they can be exceedingly effectual at keeping a network safe.
Besides, well –thought-out organizational policies can be effective at preventing unauthorized
access to critical and parts of the network.
Introduction to Computer Networks
An elementary comprehension of computer networks is essential in order to understand the
codes of network security. A network is any set of interconnected lines, basing this definition
on the current topic, a computer network is basically a set of linked computers. Networks
enable users to share resources and information, and are classified base on a variety of protocols
(Network Security Threats 2011).For instance, a classification based on the connection manner
focuses on the hardware and software systems used to link the individual computer units, such
as optical fiber, wireless connection, or coaxial cable communication. Networks can also be
categorized on scale, this gives Local Area Network (LAN), wide area Network, virtual Private
Network (VPN), among others (Stallings 2010).
Networks are made up of ‘nodes’, which are the individual computers in the network, and at
least one server and/or ‘host’ computers. The nodes are linked together by communication
systems, which may be private, such as that within an institution, or can be accessed by the
public, such as the internet. Several private networks also use the internet.
The moment a computer network is instituted, it immediately becomes vulnerable to network
security threats such as viruses and bugs that may affect the normal functioning of a computer.
Besides, the personal information such as usernames, passwords, credit card numbers and other
critical information may be at risk if the computer does not have adequate security measures.
There are very many threats in a network, some of which are so severe and can bring down a
large network consisting of thousands of computers.
Virus
In the domain of computer networks, a virus refers to a computer program that can replicate
itself, similar to the biological virus. A computer virus spreads from one computer to another
through an executable program that attaches itself on programs, files and folders.
It can spread through various means, for example, if one computer in a network becomes
‘infected’ with a virus, the rest of the computers in the network may become infected too if the
security features are inadequate.
It can also be spread through USB devices, CD, DVD, or portable had drives. A computer virus
may also spread by mailing a web address link to all addresses so that when a person clicks on
the message to go the website, the virus enters this new computer.
Certain viruses are less harmful, however, some are very harmful and can infect a computer in
the network through various ways (Simmonds 2004). A virus can corrupt the files or software
in a computer. Others may attack the computer hardware and bring the whole computer down.
Yet, some viruses may allow a person to have partial control of a computer, this allows for
unauthorized access to files and critical information stored in the computer’s hard drive.
Although the Windows platform is by far the most vulnerable, other operating systems can also
be attacked by viruses.
Network threats arising from viruses can be managed through various ways, however, the most
common technique is to install an antivirus software. UNIX-based systems such as Mac OS
and Linux are far more secure than Windows. Some anti-virus programs can scan file contents
and even zipped folders while some can also scan sent and received mails, a practice known as
‘on-access scanning’ (Simmonds 2004).Vulnerability to viruses can also be reduced by
carrying out data backups regularly on storage media that are not connected to the network or
computer. Security patches availed by software manufacturers can also assist in reducing
attacks by viruses. Secondary storage media must be scanned before opening in the host
computer.
Malware
Malware, short form of malicious software, is a program created to interrupt normal computer
operations or deny a user network or computer resources, gain partial control of the computer,
access files stored in the computer, gather network-based information such as passwords, and
other cruel or dishonest behavior (Curtin 1997).
Malware consists of a large number of malicious programs that includes viruses, Trojans
horses, worms, spyware, false adware, rootkits and other malicious programs. In 2009,
malware was listed as the second most dangerous threat to computer networks. Today, millions
of malware are created daily to exploit networks with weak security features.
Threats arising from malware can be removed using antivirus programs. Most antivirus have
an added feature of removing various malwares from the network of individual PCs. Besides,
anti-spyware software can be used to prevent spyware threats.
Denial-of-Service Attacks
A Denial-of-Service (DoS) attack is a practice aimed at making network resources unavailable
to some users. This vice entails the resolute efforts of a person or group of persons to prevent
an internet site or service functioning normally or bringing it down altogether. This network
threat is commonly committed against websites or services hosted on high profile internet
servers such as financial institutions and credit card payment services (Stallings 2010).
One mode of attack involves flooding a web server with requests in such a way that it cannot
respond to legitimate communication requests, or responds in a sluggish manner that virtually
renders it unusable. In general, DoS attacks are executed by either compelling the targeted
systems to reset, or using up its resources so that it is unable to offer the intended services.
DoS attacks are perhaps the most malicious and hardest to prevent or manage. They are the
most malicious due to the ease with which they can be launched and the difficulty of tracing
their origins, and it is difficult to deny the requests of the attacker without also blocking out
genuine requests for service.
DoS attacks can be prevented through various ways. The first technique is to use firewalls.
Firewalls have simple instructions of blocking or allowing certain IP addresses, or ports,
however, firewall are not very effective in some DoS attacks as they cannot distinguish
legitimate traffic from DoS traffic. Switches and routers can also be used to prevent these
attacks (Kizza 2006). Intrusion-prevention systems (IPS) have been successfully used to halt
DoS attacks that have signatures attached to them.
Unauthorized Access
This is a very wide terminology as it can refer to various types of attacks, however, the objective
of these attacks is to access some information that the computer or server is not supposed to
reveal. Unauthorized access to a computer or server can be achieved by using viruses, malware
and other malicious programs.
This form of threat can be waded off by using antivirus programs and security patches. Another
strategy used by intruders to access a computer on a network is a technique known as packet
sniffers. Packet sniffers can be used on a vulnerable network and they just ‘listen’ on the server
for words such as password or login in the packet stream, then sends the information thereafter
to the perpetrator.
This way, an intruder is able to obtain usernames, passwords, credit card information and other
critical information from unsuspecting users (Bragg et al 2010). This type of threat can be
prevented by using clear-text passwords, besides, data encryption can help divert such attacks.
When using a wireless network, it is advisable that one should use a long or complicated
password, also, it is advisable that the strongest security supported by the wireless connection
hardware should be used, such as encryption tools. Passwords can also be changed regularly.
General Methods for Preventing Network Attacks and Reducing Vulnerability on
Networks
The most commonly used technique for reducing network threats is the installation of antivirus
programs. These programs must be regularly updated and security patches and updates
installed. Improving the security of the network infrastructure can also involve switching on
features that enhance network security on switches, routers, and other hardware (Fadia 2006).
These security features ensure a secure connection, enhance perimeter security, prevents
intrusion, protects identity services, and general security management. Fixing intrusion
detection systems and firewalls offers protection for most areas of the network and allows for
a safe connection. Working on a virtual private network (VPN) can also enhance security. VPNs
provide network access control and encryption services.
Network security can also be improved by undertaking regular network security audits. A
network security audit simply means that an expert comes and examines the security of the
network, he also checks for loopholes that may be used attack the system and fixes them.
The audit can go beyond an inspection of the computers in the network and may comprise a
site assessment of the physical security of the organization. A network security audit fixes an
organization security flaws in the network and makes it difficult for perpetrators to attack the
network (Network Security Threats 2011).
Since network threats come in a variety of forms and cannot be totally eliminated, it is advisable
that secure updated data backups should be kept on systems that are detached from the network.
None of these strategies will singly eliminate the threats arising from a network connection,
but when they are used together, they can be exceedingly effectual at keeping a network safe.
Besides, well –thought-out organizational policies can be effective at preventing unauthorized
access to critical and parts of the network.
Introduction to Computer Networks
An elementary comprehension of computer networks is essential in order to understand the
codes of network security. A network is any set of interconnected lines, basing this definition
on the current topic, a computer network is basically a set of linked computers. Networks
enable users to share resources and information, and are classified base on a variety of protocols
(Network Security Threats 2011).For instance, a classification based on the connection manner
focuses on the hardware and software systems used to link the individual computer units, such
as optical fiber, wireless connection, or coaxial cable communication. Networks can also be
categorized on scale, this gives Local Area Network (LAN), wide area Network, virtual Private
Network (VPN), among others (Stallings 2010).
Networks are made up of ‘nodes’, which are the individual computers in the network, and at
least one server and/or ‘host’ computers. The nodes are linked together by communication
systems, which may be private, such as that within an institution, or can be accessed by the
public, such as the internet. Several private networks also use the internet.
The moment a computer network is instituted, it immediately becomes vulnerable to network
security threats such as viruses and bugs that may affect the normal functioning of a computer.
Besides, the personal information such as usernames, passwords, credit card numbers and other
critical information may be at risk if the computer does not have adequate security measures.
There are very many threats in a network, some of which are so severe and can bring down a
large network consisting of thousands of computers.
Virus
In the domain of computer networks, a virus refers to a computer program that can replicate
itself, similar to the biological virus. A computer virus spreads from one computer to another
through an executable program that attaches itself on programs, files and folders.
It can spread through various means, for example, if one computer in a network becomes
‘infected’ with a virus, the rest of the computers in the network may become infected too if the
security features are inadequate.
It can also be spread through USB devices, CD, DVD, or portable had drives. A computer virus
may also spread by mailing a web address link to all addresses so that when a person clicks on
the message to go the website, the virus enters this new computer.
Certain viruses are less harmful, however, some are very harmful and can infect a computer in
the network through various ways (Simmonds 2004). A virus can corrupt the files or software
in a computer. Others may attack the computer hardware and bring the whole computer down.
Yet, some viruses may allow a person to have partial control of a computer, this allows for
unauthorized access to files and critical information stored in the computer’s hard drive.
Although the Windows platform is by far the most vulnerable, other operating systems can also
be attacked by viruses.
Network threats arising from viruses can be managed through various ways, however, the most
common technique is to install an antivirus software. UNIX-based systems such as Mac OS
and Linux are far more secure than Windows. Some anti-virus programs can scan file contents
and even zipped folders while some can also scan sent and received mails, a practice known as
‘on-access scanning’ (Simmonds 2004).Vulnerability to viruses can also be reduced by
carrying out data backups regularly on storage media that are not connected to the network or
computer. Security patches availed by software manufacturers can also assist in reducing
attacks by viruses. Secondary storage media must be scanned before opening in the host
computer.
Malware
Malware, short form of malicious software, is a program created to interrupt normal computer
operations or deny a user network or computer resources, gain partial control of the computer,
access files stored in the computer, gather network-based information such as passwords, and
other cruel or dishonest behavior (Curtin 1997).
Malware consists of a large number of malicious programs that includes viruses, Trojans
horses, worms, spyware, false adware, rootkits and other malicious programs. In 2009,
malware was listed as the second most dangerous threat to computer networks. Today, millions
of malware are created daily to exploit networks with weak security features.
Threats arising from malware can be removed using antivirus programs. Most antivirus have
an added feature of removing various malwares from the network of individual PCs. Besides,
anti-spyware software can be used to prevent spyware threats.
Denial-of-Service Attacks
A Denial-of-Service (DoS) attack is a practice aimed at making network resources unavailable
to some users. This vice entails the resolute efforts of a person or group of persons to prevent
an internet site or service functioning normally or bringing it down altogether. This network
threat is commonly committed against websites or services hosted on high profile internet
servers such as financial institutions and credit card payment services (Stallings 2010).
One mode of attack involves flooding a web server with requests in such a way that it cannot
respond to legitimate communication requests, or responds in a sluggish manner that virtually
renders it unusable. In general, DoS attacks are executed by either compelling the targeted
systems to reset, or using up its resources so that it is unable to offer the intended services.
DoS attacks are perhaps the most malicious and hardest to prevent or manage. They are the
most malicious due to the ease with which they can be launched and the difficulty of tracing
their origins, and it is difficult to deny the requests of the attacker without also blocking out
genuine requests for service.
DoS attacks can be prevented through various ways. The first technique is to use firewalls.
Firewalls have simple instructions of blocking or allowing certain IP addresses, or ports,
however, firewall are not very effective in some DoS attacks as they cannot distinguish
legitimate traffic from DoS traffic. Switches and routers can also be used to prevent these
attacks (Kizza 2006). Intrusion-prevention systems (IPS) have been successfully used to halt
DoS attacks that have signatures attached to them.
Unauthorized Access
This is a very wide terminology as it can refer to various types of attacks, however, the objective
of these attacks is to access some information that the computer or server is not supposed to
reveal. Unauthorized access to a computer or server can be achieved by using viruses, malware
and other malicious programs.
This form of threat can be waded off by using antivirus programs and security patches. Another
strategy used by intruders to access a computer on a network is a technique known as packet
sniffers. Packet sniffers can be used on a vulnerable network and they just ‘listen’ on the server
for words such as password or login in the packet stream, then sends the information thereafter
to the perpetrator.
This way, an intruder is able to obtain usernames, passwords, credit card information and other
critical information from unsuspecting users (Bragg et al 2010). This type of threat can be
prevented by using clear-text passwords, besides, data encryption can help divert such attacks.
When using a wireless network, it is advisable that one should use a long or complicated
password, also, it is advisable that the strongest security supported by the wireless connection
hardware should be used, such as encryption tools. Passwords can also be changed regularly.
General Methods for Preventing Network Attacks and Reducing Vulnerability on
Networks
The most commonly used technique for reducing network threats is the installation of antivirus
programs. These programs must be regularly updated and security patches and updates
installed. Improving the security of the network infrastructure can also involve switching on
features that enhance network security on switches, routers, and other hardware (Fadia 2006).
These security features ensure a secure connection, enhance perimeter security, prevents
intrusion, protects identity services, and general security management. Fixing intrusion
detection systems and firewalls offers protection for most areas of the network and allows for
a safe connection. Working on a virtual private network (VPN) can also enhance security. VPNs
provide network access control and encryption services.
Network security can also be improved by undertaking regular network security audits. A
network security audit simply means that an expert comes and examines the security of the
network, he also checks for loopholes that may be used attack the system and fixes them.
The audit can go beyond an inspection of the computers in the network and may comprise a
site assessment of the physical security of the organization. A network security audit fixes an
organization security flaws in the network and makes it difficult for perpetrators to attack the
network (Network Security Threats 2011).
Since network threats come in a variety of forms and cannot be totally eliminated, it is advisable
that secure updated data backups should be kept on systems that are detached from the network.
None of these strategies will singly eliminate the threats arising from a network connection,
but when they are used together, they can be exceedingly effectual at keeping a network safe.
Besides, well –thought-out organizational policies can be effective at preventing unauthorized
access to critical and parts of the network.
Introduction to Computer Networks
An elementary comprehension of computer networks is essential in order to understand the
codes of network security. A network is any set of interconnected lines, basing this definition
on the current topic, a computer network is basically a set of linked computers. Networks
enable users to share resources and information, and are classified base on a variety of protocols
(Network Security Threats 2011).For instance, a classification based on the connection manner
focuses on the hardware and software systems used to link the individual computer units, such
as optical fiber, wireless connection, or coaxial cable communication. Networks can also be
categorized on scale, this gives Local Area Network (LAN), wide area Network, virtual Private
Network (VPN), among others (Stallings 2010).
Networks are made up of ‘nodes’, which are the individual computers in the network, and at
least one server and/or ‘host’ computers. The nodes are linked together by communication
systems, which may be private, such as that within an institution, or can be accessed by the
public, such as the internet. Several private networks also use the internet.
The moment a computer network is instituted, it immediately becomes vulnerable to network
security threats such as viruses and bugs that may affect the normal functioning of a computer.
Besides, the personal information such as usernames, passwords, credit card numbers and other
critical information may be at risk if the computer does not have adequate security measures.
There are very many threats in a network, some of which are so severe and can bring down a
large network consisting of thousands of computers.
Virus
In the domain of computer networks, a virus refers to a computer program that can replicate
itself, similar to the biological virus. A computer virus spreads from one computer to another
through an executable program that attaches itself on programs, files and folders.
It can spread through various means, for example, if one computer in a network becomes
‘infected’ with a virus, the rest of the computers in the network may become infected too if the
security features are inadequate.
It can also be spread through USB devices, CD, DVD, or portable had drives. A computer virus
may also spread by mailing a web address link to all addresses so that when a person clicks on
the message to go the website, the virus enters this new computer.
Certain viruses are less harmful, however, some are very harmful and can infect a computer in
the network through various ways (Simmonds 2004). A virus can corrupt the files or software
in a computer. Others may attack the computer hardware and bring the whole computer down.
Yet, some viruses may allow a person to have partial control of a computer, this allows for
unauthorized access to files and critical information stored in the computer’s hard drive.
Although the Windows platform is by far the most vulnerable, other operating systems can also
be attacked by viruses.
Network threats arising from viruses can be managed through various ways, however, the most
common technique is to install an antivirus software. UNIX-based systems such as Mac OS
and Linux are far more secure than Windows. Some anti-virus programs can scan file contents
and even zipped folders while some can also scan sent and received mails, a practice known as
‘on-access scanning’ (Simmonds 2004).Vulnerability to viruses can also be reduced by
carrying out data backups regularly on storage media that are not connected to the network or
computer. Security patches availed by software manufacturers can also assist in reducing
attacks by viruses. Secondary storage media must be scanned before opening in the host
computer.
Malware
Malware, short form of malicious software, is a program created to interrupt normal computer
operations or deny a user network or computer resources, gain partial control of the computer,
access files stored in the computer, gather network-based information such as passwords, and
other cruel or dishonest behavior (Curtin 1997).
Malware consists of a large number of malicious programs that includes viruses, Trojans
horses, worms, spyware, false adware, rootkits and other malicious programs. In 2009,
malware was listed as the second most dangerous threat to computer networks. Today, millions
of malware are created daily to exploit networks with weak security features.
Threats arising from malware can be removed using antivirus programs. Most antivirus have
an added feature of removing various malwares from the network of individual PCs. Besides,
anti-spyware software can be used to prevent spyware threats.
Denial-of-Service Attacks
A Denial-of-Service (DoS) attack is a practice aimed at making network resources unavailable
to some users. This vice entails the resolute efforts of a person or group of persons to prevent
an internet site or service functioning normally or bringing it down altogether. This network
threat is commonly committed against websites or services hosted on high profile internet
servers such as financial institutions and credit card payment services (Stallings 2010).
One mode of attack involves flooding a web server with requests in such a way that it cannot
respond to legitimate communication requests, or responds in a sluggish manner that virtually
renders it unusable. In general, DoS attacks are executed by either compelling the targeted
systems to reset, or using up its resources so that it is unable to offer the intended services.
DoS attacks are perhaps the most malicious and hardest to prevent or manage. They are the
most malicious due to the ease with which they can be launched and the difficulty of tracing
their origins, and it is difficult to deny the requests of the attacker without also blocking out
genuine requests for service.
DoS attacks can be prevented through various ways. The first technique is to use firewalls.
Firewalls have simple instructions of blocking or allowing certain IP addresses, or ports,
however, firewall are not very effective in some DoS attacks as they cannot distinguish
legitimate traffic from DoS traffic. Switches and routers can also be used to prevent these
attacks (Kizza 2006). Intrusion-prevention systems (IPS) have been successfully used to halt
DoS attacks that have signatures attached to them.
Unauthorized Access
This is a very wide terminology as it can refer to various types of attacks, however, the objective
of these attacks is to access some information that the computer or server is not supposed to
reveal. Unauthorized access to a computer or server can be achieved by using viruses, malware
and other malicious programs.
This form of threat can be waded off by using antivirus programs and security patches. Another
strategy used by intruders to access a computer on a network is a technique known as packet
sniffers. Packet sniffers can be used on a vulnerable network and they just ‘listen’ on the server
for words such as password or login in the packet stream, then sends the information thereafter
to the perpetrator.
This way, an intruder is able to obtain usernames, passwords, credit card information and other
critical information from unsuspecting users (Bragg et al 2010). This type of threat can be
prevented by using clear-text passwords, besides, data encryption can help divert such attacks.
When using a wireless network, it is advisable that one should use a long or complicated
password, also, it is advisable that the strongest security supported by the wireless connection
hardware should be used, such as encryption tools. Passwords can also be changed regularly.
General Methods for Preventing Network Attacks and Reducing Vulnerability on
Networks
The most commonly used technique for reducing network threats is the installation of antivirus
programs. These programs must be regularly updated and security patches and updates
installed. Improving the security of the network infrastructure can also involve switching on
features that enhance network security on switches, routers, and other hardware (Fadia 2006).
These security features ensure a secure connection, enhance perimeter security, prevents
intrusion, protects identity services, and general security management. Fixing intrusion
detection systems and firewalls offers protection for most areas of the network and allows for
a safe connection. Working on a virtual private network (VPN) can also enhance security. VPNs
provide network access control and encryption services.
Network security can also be improved by undertaking regular network security audits. A
network security audit simply means that an expert comes and examines the security of the
network, he also checks for loopholes that may be used attack the system and fixes them.
The audit can go beyond an inspection of the computers in the network and may comprise a
site assessment of the physical security of the organization. A network security audit fixes an
organization security flaws in the network and makes it difficult for perpetrators to attack the
network (Network Security Threats 2011).
Since network threats come in a variety of forms and cannot be totally eliminated, it is advisable
that secure updated data backups should be kept on systems that are detached from the network.
None of these strategies will singly eliminate the threats arising from a network connection,
but when they are used together, they can be exceedingly effectual at keeping a network safe.
Besides, well –thought-out organizational policies can be effective at preventing unauthorized
access to critical and parts of the network.
Introduction to Computer Networks
An elementary comprehension of computer networks is essential in order to understand the
codes of network security. A network is any set of interconnected lines, basing this definition
on the current topic, a computer network is basically a set of linked computers. Networks
enable users to share resources and information, and are classified base on a variety of protocols
(Network Security Threats 2011).For instance, a classification based on the connection manner
focuses on the hardware and software systems used to link the individual computer units, such
as optical fiber, wireless connection, or coaxial cable communication. Networks can also be
categorized on scale, this gives Local Area Network (LAN), wide area Network, virtual Private
Network (VPN), among others (Stallings 2010).
Networks are made up of ‘nodes’, which are the individual computers in the network, and at
least one server and/or ‘host’ computers. The nodes are linked together by communication
systems, which may be private, such as that within an institution, or can be accessed by the
public, such as the internet. Several private networks also use the internet.
The moment a computer network is instituted, it immediately becomes vulnerable to network
security threats such as viruses and bugs that may affect the normal functioning of a computer.
Besides, the personal information such as usernames, passwords, credit card numbers and other
critical information may be at risk if the computer does not have adequate security measures.
There are very many threats in a network, some of which are so severe and can bring down a
large network consisting of thousands of computers.
Virus
In the domain of computer networks, a virus refers to a computer program that can replicate
itself, similar to the biological virus. A computer virus spreads from one computer to another
through an executable program that attaches itself on programs, files and folders.
It can spread through various means, for example, if one computer in a network becomes
‘infected’ with a virus, the rest of the computers in the network may become infected too if the
security features are inadequate.
It can also be spread through USB devices, CD, DVD, or portable had drives. A computer virus
may also spread by mailing a web address link to all addresses so that when a person clicks on
the message to go the website, the virus enters this new computer.
Certain viruses are less harmful, however, some are very harmful and can infect a computer in
the network through various ways (Simmonds 2004). A virus can corrupt the files or software
in a computer. Others may attack the computer hardware and bring the whole computer down.
Yet, some viruses may allow a person to have partial control of a computer, this allows for
unauthorized access to files and critical information stored in the computer’s hard drive.
Although the Windows platform is by far the most vulnerable, other operating systems can also
be attacked by viruses.
Network threats arising from viruses can be managed through various ways, however, the most
common technique is to install an antivirus software. UNIX-based systems such as Mac OS
and Linux are far more secure than Windows. Some anti-virus programs can scan file contents
and even zipped folders while some can also scan sent and received mails, a practice known as
‘on-access scanning’ (Simmonds 2004).Vulnerability to viruses can also be reduced by
carrying out data backups regularly on storage media that are not connected to the network or
computer. Security patches availed by software manufacturers can also assist in reducing
attacks by viruses. Secondary storage media must be scanned before opening in the host
computer.
Malware
Malware, short form of malicious software, is a program created to interrupt normal computer
operations or deny a user network or computer resources, gain partial control of the computer,
access files stored in the computer, gather network-based information such as passwords, and
other cruel or dishonest behavior (Curtin 1997).
Malware consists of a large number of malicious programs that includes viruses, Trojans
horses, worms, spyware, false adware, rootkits and other malicious programs. In 2009,
malware was listed as the second most dangerous threat to computer networks. Today, millions
of malware are created daily to exploit networks with weak security features.
Threats arising from malware can be removed using antivirus programs. Most antivirus have
an added feature of removing various malwares from the network of individual PCs. Besides,
anti-spyware software can be used to prevent spyware threats.
Denial-of-Service Attacks
A Denial-of-Service (DoS) attack is a practice aimed at making network resources unavailable
to some users. This vice entails the resolute efforts of a person or group of persons to prevent
an internet site or service functioning normally or bringing it down altogether. This network
threat is commonly committed against websites or services hosted on high profile internet
servers such as financial institutions and credit card payment services (Stallings 2010).
One mode of attack involves flooding a web server with requests in such a way that it cannot
respond to legitimate communication requests, or responds in a sluggish manner that virtually
renders it unusable. In general, DoS attacks are executed by either compelling the targeted
systems to reset, or using up its resources so that it is unable to offer the intended services.
DoS attacks are perhaps the most malicious and hardest to prevent or manage. They are the
most malicious due to the ease with which they can be launched and the difficulty of tracing
their origins, and it is difficult to deny the requests of the attacker without also blocking out
genuine requests for service.
DoS attacks can be prevented through various ways. The first technique is to use firewalls.
Firewalls have simple instructions of blocking or allowing certain IP addresses, or ports,
however, firewall are not very effective in some DoS attacks as they cannot distinguish
legitimate traffic from DoS traffic. Switches and routers can also be used to prevent these
attacks (Kizza 2006). Intrusion-prevention systems (IPS) have been successfully used to halt
DoS attacks that have signatures attached to them.
Unauthorized Access
This is a very wide terminology as it can refer to various types of attacks, however, the objective
of these attacks is to access some information that the computer or server is not supposed to
reveal. Unauthorized access to a computer or server can be achieved by using viruses, malware
and other malicious programs.
This form of threat can be waded off by using antivirus programs and security patches. Another
strategy used by intruders to access a computer on a network is a technique known as packet
sniffers. Packet sniffers can be used on a vulnerable network and they just ‘listen’ on the server
for words such as password or login in the packet stream, then sends the information thereafter
to the perpetrator.
This way, an intruder is able to obtain usernames, passwords, credit card information and other
critical information from unsuspecting users (Bragg et al 2010). This type of threat can be
prevented by using clear-text passwords, besides, data encryption can help divert such attacks.
When using a wireless network, it is advisable that one should use a long or complicated
password, also, it is advisable that the strongest security supported by the wireless connection
hardware should be used, such as encryption tools. Passwords can also be changed regularly.
General Methods for Preventing Network Attacks and Reducing Vulnerability on
Networks
The most commonly used technique for reducing network threats is the installation of antivirus
programs. These programs must be regularly updated and security patches and updates
installed. Improving the security of the network infrastructure can also involve switching on
features that enhance network security on switches, routers, and other hardware (Fadia 2006).
These security features ensure a secure connection, enhance perimeter security, prevents
intrusion, protects identity services, and general security management. Fixing intrusion
detection systems and firewalls offers protection for most areas of the network and allows for
a safe connection. Working on a virtual private network (VPN) can also enhance security. VPNs
provide network access control and encryption services.
Network security can also be improved by undertaking regular network security audits. A
network security audit simply means that an expert comes and examines the security of the
network, he also checks for loopholes that may be used attack the system and fixes them.
The audit can go beyond an inspection of the computers in the network and may comprise a
site assessment of the physical security of the organization. A network security audit fixes an
organization security flaws in the network and makes it difficult for perpetrators to attack the
network (Network Security Threats 2011).
Since network threats come in a variety of forms and cannot be totally eliminated, it is advisable
that secure updated data backups should be kept on systems that are detached from the network.
None of these strategies will singly eliminate the threats arising from a network connection,
but when they are used together, they can be exceedingly effectual at keeping a network safe.
Besides, well –thought-out organizational policies can be effective at preventing unauthorized
access to critical and parts of the network.
