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Computer Virus, Internet Security

and Firewalls

Reeba Mary Jose

S1, MBA IBROLL NO: 16

School of Management StudiesCUSAT, Kochi 22

E-mail : [email protected]

Abstract:This paper gives an overview about what computer viruses, internetsecurity and firewalls are, how the viruses works and the need for internetsecurity 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 foralmost every purposes. Most personal computers are now connested to the Internet and tolocal area networks which facilitate the spread of malicious code. With each day, computerviruses are becoming more and more complex , difficult to detect and avoid them. Hencethere is a need to protect our files and other documents in the computer from very harmfulviruses which can cause great damage. In order to protect the computer systems frombeing attacked by viruses, appropriate measures should be taken to ensure internetsecurity and firewalls must be installed on every computers.


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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 wormI Love YouCode Red

A virus can be either transient or resident. A transient virus is a virus that runs whenits attached program executes and terminates when its attached program ends. Thisvirus spreads its infection to other programmers during execution. A resident viruslocates itself in the memory and can remain active or be activated as a standaloneprogram, 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 isactivated.

They insert a copy of itself into the executable program file before the firstexecutable instruction

All virus instructions are executed first and after the last virus instruction, controlfloes naturally to the first program instruction.


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3. INTERNET SECURITY

Internet Security involves protection of a computers internet account & files fromIntrusion of an unknown user.

Basic Security Measures used are:i) p se of passwordsii) Change of file permissionsiii) Back up of computers data

3.1 Importance of Internet Security

Prevents and detects unauthorized use of your computer q 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.

3.2Stepsto Protect Internet Connected Computer

r . Buy a hardware based firewall as it hides your computer from rest of the internet.It is a good primary defense.

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. t se antivirus software & update it regularly to check for latest viruses. Antivirussoftware checks individual

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. t se Anti-spyware Software. Avoid clicking on pop-up windows to reduce chancesof Spyware infection. Click on the X on the pop-up window, instead of Closebutton.Example: Windows LiveOneCare , SpySweeper(egs)

4. t pdate your computers system and the Web browsing software regularly. Ithelps to improve functionality and fixes internal bugs .

5. Have knowledge about spoofs and phishes. Avoid giving your personalinformation like password, bank account number or social security numbers replyto any e-mail.

4.0 FIREWALLS

v irewalls are device that filters all traffic between a protected Inside network and a lesstrustworthy Outside network. The purpose of firewall is to keep bad things outside aprotected environment. v irewall is a dedicated appliance, or software running on acomputer, which inspects network traffic passing through it, and denies or permitspassage based on a set of rules. It can be both hardware and Software. v irewalls are amust 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 w irewalls

Hardware based Firewalls-Runs on a dedicated computer-Better performance than Software x 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 blockeverything else.

4.3 Firewall Techniques

1. Packet Filteriny

Data travels as small pieces called packets Each packet has Metadata which contains informations 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 tothe 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 Applies security mechanisms when a TCP or DP connection is

established.

Once the connection is made, packets can flow between the hosts withoutfurther checking.

5.0 CONCLUSION

In the present world, most personal computers are now connected to the Internet andviruses are becoming more complex as days go by. Hence it has now become a crucialtask to protect our computer systems against them. For this purpose, we can installeffective anti-virus softwares and see to it that we periodically update them. We shouldalso ensure security using Firewalls.Firewalls should be installed on all computers.

6.0 REFERENCES

1. Charles P. Pfleeger, Shari Lawrence Pfleeger, 2002, Security in computing , PearsonEducation,. Third Edn.

2. http://www.howstuffworks.com/virus.htm, downloaded on 12.09.20093. http://www.en.wikipedia.org/wiki/Computervirus , downloaded on 12.09.20094. http://www.armor2net.com/knowledge/internet_security.htm, downloaded on

19.09.20095. http://www.ehow.com/articles-3367-antivirus-software.htm, downloaded on 19.09.20096. http://www.ibibo.com , downloaded on 19.09.20097. http://en.wikipedia.org/wiki/Firewall , downloaded on 11.09.20098. http://www.webopedia.com/TERM/Firewall.html , downloaded on 11.09.20099. http://www.freebsd.org/doc/en/books/handbook/firewalls-concepts.html, downloaded

on 11.09.2009

10. http://www.wisegeek.com , downloaded on 11.09.200911. http://www.howstuffworks.com/firewall.htm , downloaded on 12.09.200912. http://www.armor2net.com/knowledge/computer-security.htm, downloaded on

19.09.200913. http://www.sawaal.ibibo.com/search/overcome-virus-come, downloaded on 19.09.200914. http://farmindustrynew.com/mag/farming_steps_overcome_internet/, downloaded on

19.09.200915. http://www.searchsecurity.techtarget.com/sDefinition/ , downloaded on 19.09.200916. http://www.armor2net.com/knowledge/firewall_protection.htm , downloaded on

19.09.2009


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