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INTRODUCTION


you have heard about viruses causing health problems such as fever and other diseases. viruses are harmful germs that cause damage to anyone they attack.

 have you heard about viruses attacking computer systems? these viruses are different from the harmful viruses that cause diseases.


COMPUTER VIRUS


A virus that attacks a computer is actually a computer program that is deliberately written by bad guys called virus programmers a virus program is not always harmful. any program that causes harm to a computer system is not always a virus.

 A computer virus in real terms is a program that can copy itself to a different location on the same computer or try to infect different computers automatically. the full form of VIRUS is vital information resources under seize.

HARM CAUSED BY COMPUTER VIRUSES


the majority of the virus program is harmful. their main purpose is to irritate the computer users these viruses are written by same people just for fun. but other viruses are malicious and can be very harmful to a computer system. they fill up the Sisk's space of a computer by copying itself endless times they can modify or corrupt important files, delete information fro file, steal your account number and password and send them to other people through the internet. this process happens so quickly that you may not even be aware of the presence of a virus on your computer.

HOW DO YOU GET A COMPUTER VIRUS


viruses attack your computer and infect it in several ways. some of the most common ways in wich your computer gets a virus are :

 * through an infected CD or pen drive.

 * through e-mail attachments.

 * visiting malicious websites and downloading infected files.

 * starting an infected application as it infects other running application as it infects other running application


HISTORY OF COMPUTER VIRUSES


traditional computer viruses emerged in 1980. in 1982, Rich skrenta, created a virus named EIK cloner that attached itself to the Apple DOS 3.3aperating system and spread by floppy disk.

 the first PC virus was a boot sector virus called (c) brain it was created in 1986 by two brothers basit and A.F  ALVI the brothers created the virus to prevent pirated copies of software they had written.

 since the mid-1990s, macro viruses have become common. most of these viruses are written in the scripting languages for Microsoft programs such as Microsoft Word and Microsoft excel these viruses spread by excel spreadsheets and other Microsoft Office documents.

 nowadays one of the most common means of virus infection is through instant messaging or internet chat software e-mail is the biggest means to spread viruses worldwide.

TYPE OF COMPUTER VIRUSES


there are many types of viruses and different people may describe them in different ways. let us know about some of the specific categories of viruses.

 BOMBS- these are the viruses that active themselves after a specific time period and cause damage to the computer system.

 BOOT SECTOR VIRUSES - the boot sector is the area of the hard disk that stores valuable information boot sector viruses affect this area and cause damages these are very harmful viruses.

 E-MAIL VIRUSES -these viruses transmit through e-mail and the attached files when the person opens the attached file, the virus copies itself to his or her computer hard disk and cause damage.

 TROJAN HORSES- these viruses at first appear to be friendly but are very malicious programs they steal information from the computer. they can be of any type. even some computer games are trojan horses virus.

 WORMS - A WORMS is a malicious program that duplicates itself. they eventually fill up the disk space with copies of itself and thereby make a computer system to work very slow.

 SPYWARE- A SPYWARE is computer software that is installed secretly on a computer to gather a person's personal information without his/her knowledge or consent.


MALWARE

malware is derived from the words malicious and software it is the type of software designed to damage the data/computer system without the owner's knowledge or consent malware includes computer viruses, worms, trojan, horses, spyware, and other malicious and unwanted software.

PROTECTING YOUR COMPUTER 

protecting your computer from viruses is not a difficult task. you already know-how viruses infect a computer system or how they spread. to protect your computer from viruses, keep in mind the following points: 


* Do not use the CD or the pen drive received from another person unless you the certain that the device does not contain the virus. 

* Do, not download programs or other information from non-reputed sources on the internet. 

* Be careful of the attached files you receive in your e-mail open only those files sent by the people you trust.

* Restrict access to your system 

* Install an antivirus program on your computer. 



ANTIVIRUS 


Antivirus programs check the files on your computer to detect the viruses and also to remove them.


there are many antivirus programs available in the market. you may install an antivirus program on your computer in order to prevent it from being attacked by computer viruses.


same of the popular antivirus software  

 * Norton 

 * Kaspersky 

 * Mc Afee

 * F-secure

 * AVG

 * K7Endpoint security