Computer virus: Difference between revisions

Revision as of 13:13, 13 October 2005

Revision as of 21:54, 13 October 2005

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See also [http://news.bbc.co.uk/1/hi/technology/3172967.stm BBC News' Why people write computer viruses]

== Replication Strategies ==

== monkey men

In order to replicate itself, a virus must be permitted to execute code and write to memory. For this reason, many viruses attach themselves to executable files that may be part of legitimate programs. If a user tries to start an infected program, the virus' code may be executed first. Viruses can be divided into two types, on the basis of their behavior when they get executed. Nonresident viruses immediately search for other hosts that can be infected, infect these targets, and finally transfer control to the application program they infected. Resident viruses do not search for hosts when they are started. Instead, a resident virus loads itself into memory on execution and transfers control to the host program. The virus stays active in the background and infects new hosts when those files are accessed by other programs or the operating system itself.