Virus
A virus is a program to change the way a computer operates, without the permission or knowledge of the user. It copies a computer boot sector or document. Some viruses are programmed to damage the computer by deleting files or reformatting the hard disk. Others are designed to duplicate themselves and make their presence by presenting a text, video, and audio messages. In 1983, Fred Cohen coined the computer virus. He said a virus is “a program that can ‘infect’ other programs by modifying them to include a possibly evolved copy of itself.”
There are two criteria’s of viruses.
-It must execute itself::it places its own code in the path of execution of another program
-It must replicate itself::it replaces other executable files with a copy of the virus infected file.
Viruses can easily spread by e-mail messages or instant messaging messages. That’s why you should never open an e-mail attachments unless you know who it’s from and that you know that you’re suppose to accept it. To avoid viruses, you should keep your computer current with the latest updates and antivirus tools. You should also stay informed about recent threats.
These are the 5 most recognized viruses
-File infection viruses
-Book sector viruses
-Master boot record viruses
-Multiplicative viruses
-Macro viruses
MLA
“What is the difference between viruses, worms, and Trojans?.” 1 Dec 2008 <http://service1.symantec.com/support/nav.nsf/docid/1999041209131106>.
“What is virus? – a definition from Whatis.com.” 1 Dec 2008 <http://searchsecurity.techtarg434et.com/sDefinition/0,,sid14_gci213306,00.html>.
“What is a virus?.” 1 Dec 2008 <http://antivirus.about.com/cs/tutorials/a/whatisavirus.htm>.
“Computer Viruses: What is a Computer Virus? | Microsoft Security;.” 1 Dec 2008 <http://www.microsoft.com/protect/computer/basics/virus.mspx>.
