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Computer Virus


Meaning :  computer virus is a destructive computer program that replicates itself causing loss of data and program. It is developed by computer programmer using Assembly or low level language. Eg. Cbrain, Time bomb, June 12, etc.

Features:

(i)                 Self- replicating

(ii)               Quick transmitting

(iii)             Destructive

 

Purpose of creating Virus :

(i)                 To Percocet software from piracy

(ii)               To delete , steal and damage data and program

(iii)             To entertain user

(iv)             To earn money with bad intention

 

Types of Computer virus :

(i)                 Boot sector virus:  Infects boot sector of a disk.

(ii)               Application infector/ File virus:  The virus which infects the file having extension .com. .exe. .drv etc is known as file virus.

(iii)             Dos System infector : The virus which infects the system files of MS–DOS( IO.sys, MSDOS.sys. COMMAND. com) is known as DOS system infector.

(iv)             Macro virus: Infects MS- word and Excel document template .

(v)               Script virus: Infects Html and java scripting language. 

 

Symptoms/ Indication of virus infection :

(i)                 Computer takes long time to boot.

(ii)               Computer becomes hang and slow down, all of sudden

(iii)             Size of file is changed, all of sudden.

(iv)             Data and files are deleted or automatically copied.

(v)               Disk drives are accessed without selection

 

Methods/ Modes of virus transmission/ infiltration:

(i)  By using pirated software.

(ii) By using virus infected disks and games.

(iii) By down loading unknowns site and mail.             

 

Safety  from the computer virus :

(i) Do not down load or copy any program from internet, without confirmation of virus free.

(ii) Do not use virus infected disk or media without scanning.

(iii) Always use updated & latest antivirus program.

( iv) Keep back up of important data & program.

 

Antivirus program : A software that scans , detect and remove virus from program or computer system is known as antivirus program. The process of detecting and removing virus is called virus scanning  Exampes;  SCAN, CLEAN, MSAV, CPAV, AVG