16-Computer Virus, Internet Security
Content
Computer Virus, Internet Security and Firewalls
Reeba Mary Jose
S1, MBA ² IB ROLL NO: 16 School of Management Studies CUSAT, Kochi ² 22 E-mail : [email protected]
Abstract: This paper gives an overview about what computer viruses, internet security and firewalls are, how the viruses works and the need for internet security and firewalls. Key Words : Virus, Internet security, firewalls
1.0 INTRODUCTION
In this fast moving world, the importance of computer is increasing as they are used for almost every purposes. Most personal computers are now connested to the Internet and to local area networks which facilitate the spread of malicious code. With each day, computer viruses are becoming more and more complex , difficult to detect and avoid them. Hence there is a need to protect our files and other documents in the computer from very harmful viruses which can cause great damage. In order to protect the computer systems from being attacked by viruses, appropriate measures should be taken to ensure internet security and firewalls must be installed on every computers.
2.0 COMPUTER VIRUS
A computer virus is a computer program that can copy itself & infect a computer without the permission or knowledge of the owner. Examples: Storm worm I Love You Code Red A virus can be either transient or resident. A transient virus is a virus that runs when its attached program executes and terminates when its attached program ends. This virus spreads its infection to other programmers¶ during execution. A resident virus locates itself in the memory and can remain active or be activated as a standalone program, even after its attached program ends.
2.1 How Computer Viruses Attach
A computer virus may attach itself to a program by several ways: Appended viruses Viruses that surround a program Integrated viruses and replacements Document Viruses
Appended Viruses
Virus attaches itself to the program, whenever the program is run, the virus is activated. They insert a copy of itself into the executable program file before the first executable instruction All virus instructions are executed first and after the last virus instruction, control floes naturally to the first program instruction.
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The i epl es some of its t et i tegrati g itself i to he origi al ode of the target. ere the irus riter has to ow the exact structure of the origi al program i order to ow where to i sert which pieces of the irus.
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This the most popular irus t pe currentl . This is implemented within a formatted document, such as a written document, a database, a slide presentation, or a spreadsheet. The writer of the document iruses may use any features of these highly structured files such as data, commands, macros , procedures or system calls to perform malicious actions. The writer includes the irus in the command part of the document and hence the user usually sees only the content of the document.
Use more secure operating system li e UNIX In case of unsecured operating system, then buy a irus protection software. A oid programs from unknown sources, like the Internet. Ensure that acro Virus Protection is enabled on all icrosoft applications. Never double click an e-mail attachment that contains an executable.
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3. INTERNET SECURITY
Internet Security involves protection of a computer¶s internet account & files from Intrusion of an unknown user. Basic Security Measures used are: i) se of passwords ii) Change of file permissions iii) Back up of computer¶s data
3.1 Importance of Internet Security
Prevents and detects unauthorized use of your computer orged e-mails can be prevented Can avoid personal information examination on our computer by an intruder(financial statements) Can avoid giving hide outs to hackers, who launch attacks against high profile systems.
3.2 Steps to Protect Internet Connected Computer
. . . Buy a hardware based firewall as it hides your computer from rest of the internet. It is a good primary defense. se antivirus software & update it regularly to check for latest viruses. Antivirus software checks individual se Anti-spyware Software. Avoid clicking on pop-up windows to reduce chances of Spyware infection. Click on the ³X´ on the pop-up window, instead of ³Close´ button. Example: Windows LiveOneCare , SpySweeper(egs) pdate your computer¶s system and the Web browsing software regularly. It helps to improve functionality and fixes internal bugs . Have knowledge about spoofs and phishes. Avoid giving your personal information like password, bank account number or social security numbers reply to any e-mail.
5.
4.0 FIREWALLS
irewalls are device that filters all traffic between a protected ³Inside network´ and a less trustworthy ³Outside network´. The purpose of firewall is to keep bad things outside a protected environment. irewall is a dedicated appliance, or software running on a computer, which inspects network traffic passing through it, and denies or permits passage based on a set of rules. It can be both hardware and Software. irewalls are a must in order to ensure the security of the computer.
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4.1Types Of Firewalls
Software based firewalls - Run as additional programs on computers. - Known as Personal irewalls Hardware based Firewalls -Runs on a dedicated computer -Better performance than Software irewalls - More expensive
4.2 Two Ways to Create Firewall Rule sets:
Exclusive -Firewall allows all traffic through except, for the traffic matching the rule set. Inclusive -Firewall allows only those traffic that matches the rule sets and block everything else.
4.3 Firewall Techniques
1. Packet Filterin Data travels as small pieces called packets Each packet has ³Metadata´ which contains information¶s like where it is coming from and where it should be sent to. Based on the rules, packets are dropped or rejected All Firewalls can do this. 2. Stateful Packet Inspection This keeps track of connections. Compares key parts of the packet to a database of trusted information. Packet can be the start of a new connection or it can be a part of an existing connection. If it is neither of the two, it is considered useless and will be dropped. 3. Application layer Firewalls They look at the actual data transported. They know how certain protocols work. E.g.: FTP, HTTP Looks if data in a packet is valid for a protocol. If it is not, it can be dropped. It is very effective, but can impose performance degradation. 4. Proxy Service Information from the internet is retrieved by the Firewall and then sent to the requesting system and vice versa. Intercepts all messages entering and leaving the network. Effectively hides the true network addresses.
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5. Circuit level ateway DP connection is Applies security mechanisms when a TCP or established. Once the connection is made, packets can flow between the hosts without further checking.
5.0 CONCLUSION
In the present world, most personal computers are now connected to the Internet and viruses are becoming more complex as days go by. Hence it has now become a crucial task to protect our computer systems against them. For this purpose, we can install effective anti-virus software¶s and see to it that we periodically update them. We should also ensure security using Firewalls. Firewalls should be installed on all computers.
6.0 REFERENCES 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. Charles P. Pfleeger, Shari Lawrence Pfleeger, 2002, ´ Security in computingµ , Pearson Education,. Third Edn. http://www.howstuffworks.com/virus.htm, downloaded on 12.09.2009 http://www.en.wikipedia.org/wiki/Computervirus , downloaded on 12.09.2009 http://www.armor2net.com/knowledge/internet_security.htm , downloaded on 19.09.2009 http://www.ehow.com/articles -3367-antivirus-software.htm , downloaded on 19.09.2009 http://www.ibibo.com , downloaded on 19.09.2009 http://en.wikipedia.org/wiki/Firewall , downloaded on 11.09.2009 http://www.webopedia.com/TERM/Firewall.html , downloaded on 11.09.2009 http://www.freebsd.org/doc/en/books/handbook/firewalls-concepts.html , downloaded on 11.09.2009 http://www.wisegeek.com , downloaded on 11.09.2009 http://www.howstuffworks.com/firewall.htm , downloaded on 12.09.2009 http://www.armor2net.com/knowledge/computer-security.htm , downloaded on 19.09.2009 http://www.sawaal.ibibo.com/search/overcome-virus-come , downloaded on 19.09.2009 http://farmindustrynew.com/mag/farming_steps_overcome_internet/ , downloaded on 19.09.2009 http://www.searchsecurity.techtarget.com/sDefinition/ , downloaded on 19.09.2009 http://www.armor2net.com/knowledge/firewall_protection.htm , downloaded on 19.09.2009
Reeba Mary Jose
S1, MBA ² IB ROLL NO: 16 School of Management Studies CUSAT, Kochi ² 22 E-mail : [email protected]
Abstract: This paper gives an overview about what computer viruses, internet security and firewalls are, how the viruses works and the need for internet security and firewalls. Key Words : Virus, Internet security, firewalls
1.0 INTRODUCTION
In this fast moving world, the importance of computer is increasing as they are used for almost every purposes. Most personal computers are now connested to the Internet and to local area networks which facilitate the spread of malicious code. With each day, computer viruses are becoming more and more complex , difficult to detect and avoid them. Hence there is a need to protect our files and other documents in the computer from very harmful viruses which can cause great damage. In order to protect the computer systems from being attacked by viruses, appropriate measures should be taken to ensure internet security and firewalls must be installed on every computers.
2.0 COMPUTER VIRUS
A computer virus is a computer program that can copy itself & infect a computer without the permission or knowledge of the owner. Examples: Storm worm I Love You Code Red A virus can be either transient or resident. A transient virus is a virus that runs when its attached program executes and terminates when its attached program ends. This virus spreads its infection to other programmers¶ during execution. A resident virus locates itself in the memory and can remain active or be activated as a standalone program, even after its attached program ends.
2.1 How Computer Viruses Attach
A computer virus may attach itself to a program by several ways: Appended viruses Viruses that surround a program Integrated viruses and replacements Document Viruses
Appended Viruses
Virus attaches itself to the program, whenever the program is run, the virus is activated. They insert a copy of itself into the executable program file before the first executable instruction All virus instructions are executed first and after the last virus instruction, control floes naturally to the first program instruction.
¢$ $# ¥ " ¥¡ # ¤£¦" ¥¥¦§ #
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§¢ §¦ ¥
¤¢ &¢ ¢¤ £ ¢% $"¥ ¤ "!# " ¥¢¤ ¥" £ )§ ¤ ¢ £" §¢ " £ § ¢ § &¦¥ §£" & # $# ¥ " ¥¡ # " ¢ § &# # (#$ §¦¥ ! ¢ £" ¦ &¢'¢ § ¥¢ # ¤ £# ¢ ¥" ¢% "¥ £" & §# ¦% $# ¥ " ¥¡ #£ ¥" ¢ §£¦¥ §¦¥ ! ¢ ¨ ¨ ©¨¨© ©¨ §¦¥
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t l t
f t t
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ft
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t
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The i epl es some of its t et i tegrati g itself i to he origi al ode of the target. ere the irus riter has to ow the exact structure of the origi al program i order to ow where to i sert which pieces of the irus.
m
Vi
This the most popular irus t pe currentl . This is implemented within a formatted document, such as a written document, a database, a slide presentation, or a spreadsheet. The writer of the document iruses may use any features of these highly structured files such as data, commands, macros , procedures or system calls to perform malicious actions. The writer includes the irus in the command part of the document and hence the user usually sees only the content of the document.
Use more secure operating system li e UNIX In case of unsecured operating system, then buy a irus protection software. A oid programs from unknown sources, like the Internet. Ensure that acro Virus Protection is enabled on all icrosoft applications. Never double click an e-mail attachment that contains an executable.
i
g
f
i
h
2.2 P
i
Ag i
Vi
V
U
V
U
eW d
U
Q
Fig . 3 I tegrated iruses and
eplacement
C G 8
F
G
G
G
GP G FE
D9B
GP
I
b Yd c
63 727
8
G
8
bX a XW Y `Y
CB
H
0 6TSR 1 2
5
I
g
Vi
63 727
9 A@9 8 G
3 0 214 21 G
3. INTERNET SECURITY
Internet Security involves protection of a computer¶s internet account & files from Intrusion of an unknown user. Basic Security Measures used are: i) se of passwords ii) Change of file permissions iii) Back up of computer¶s data
3.1 Importance of Internet Security
Prevents and detects unauthorized use of your computer orged e-mails can be prevented Can avoid personal information examination on our computer by an intruder(financial statements) Can avoid giving hide outs to hackers, who launch attacks against high profile systems.
3.2 Steps to Protect Internet Connected Computer
. . . Buy a hardware based firewall as it hides your computer from rest of the internet. It is a good primary defense. se antivirus software & update it regularly to check for latest viruses. Antivirus software checks individual se Anti-spyware Software. Avoid clicking on pop-up windows to reduce chances of Spyware infection. Click on the ³X´ on the pop-up window, instead of ³Close´ button. Example: Windows LiveOneCare , SpySweeper(egs) pdate your computer¶s system and the Web browsing software regularly. It helps to improve functionality and fixes internal bugs . Have knowledge about spoofs and phishes. Avoid giving your personal information like password, bank account number or social security numbers reply to any e-mail.
5.
4.0 FIREWALLS
irewalls are device that filters all traffic between a protected ³Inside network´ and a less trustworthy ³Outside network´. The purpose of firewall is to keep bad things outside a protected environment. irewall is a dedicated appliance, or software running on a computer, which inspects network traffic passing through it, and denies or permits passage based on a set of rules. It can be both hardware and Software. irewalls are a must in order to ensure the security of the computer.
v
v
t
4.
t
t
q
p
s r u v
4.1Types Of Firewalls
Software based firewalls - Run as additional programs on computers. - Known as Personal irewalls Hardware based Firewalls -Runs on a dedicated computer -Better performance than Software irewalls - More expensive
4.2 Two Ways to Create Firewall Rule sets:
Exclusive -Firewall allows all traffic through except, for the traffic matching the rule set. Inclusive -Firewall allows only those traffic that matches the rule sets and block everything else.
4.3 Firewall Techniques
1. Packet Filterin Data travels as small pieces called packets Each packet has ³Metadata´ which contains information¶s like where it is coming from and where it should be sent to. Based on the rules, packets are dropped or rejected All Firewalls can do this. 2. Stateful Packet Inspection This keeps track of connections. Compares key parts of the packet to a database of trusted information. Packet can be the start of a new connection or it can be a part of an existing connection. If it is neither of the two, it is considered useless and will be dropped. 3. Application layer Firewalls They look at the actual data transported. They know how certain protocols work. E.g.: FTP, HTTP Looks if data in a packet is valid for a protocol. If it is not, it can be dropped. It is very effective, but can impose performance degradation. 4. Proxy Service Information from the internet is retrieved by the Firewall and then sent to the requesting system and vice versa. Intercepts all messages entering and leaving the network. Effectively hides the true network addresses.
x
w
y
5. Circuit level ateway DP connection is Applies security mechanisms when a TCP or established. Once the connection is made, packets can flow between the hosts without further checking.
5.0 CONCLUSION
In the present world, most personal computers are now connected to the Internet and viruses are becoming more complex as days go by. Hence it has now become a crucial task to protect our computer systems against them. For this purpose, we can install effective anti-virus software¶s and see to it that we periodically update them. We should also ensure security using Firewalls. Firewalls should be installed on all computers.
6.0 REFERENCES 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. Charles P. Pfleeger, Shari Lawrence Pfleeger, 2002, ´ Security in computingµ , Pearson Education,. Third Edn. http://www.howstuffworks.com/virus.htm, downloaded on 12.09.2009 http://www.en.wikipedia.org/wiki/Computervirus , downloaded on 12.09.2009 http://www.armor2net.com/knowledge/internet_security.htm , downloaded on 19.09.2009 http://www.ehow.com/articles -3367-antivirus-software.htm , downloaded on 19.09.2009 http://www.ibibo.com , downloaded on 19.09.2009 http://en.wikipedia.org/wiki/Firewall , downloaded on 11.09.2009 http://www.webopedia.com/TERM/Firewall.html , downloaded on 11.09.2009 http://www.freebsd.org/doc/en/books/handbook/firewalls-concepts.html , downloaded on 11.09.2009 http://www.wisegeek.com , downloaded on 11.09.2009 http://www.howstuffworks.com/firewall.htm , downloaded on 12.09.2009 http://www.armor2net.com/knowledge/computer-security.htm , downloaded on 19.09.2009 http://www.sawaal.ibibo.com/search/overcome-virus-come , downloaded on 19.09.2009 http://farmindustrynew.com/mag/farming_steps_overcome_internet/ , downloaded on 19.09.2009 http://www.searchsecurity.techtarget.com/sDefinition/ , downloaded on 19.09.2009 http://www.armor2net.com/knowledge/firewall_protection.htm , downloaded on 19.09.2009
