A commonly used term for any kind of malware.

Originally, by analogy with biological viruses, via science fiction, "virus" meant software that "infects" other programs by embedding a copy of itself in them, so that they become Trojan horses. Executing an infected program would run the virus too, allowing it to propagate, normally without the user's knowledge.

A virus has an "engine" - code that enables it to propagate - and may also have a "payload" - what it does apart from propagating. It needs a "host" the particular hardware and software environment on which it can run and a "trigger" - the event that starts it running.

Unlike a worm, a virus cannot infect other computers without assistance. It is propagated by vectors such as users downloading infected software.

Viruses written by particularly antisocial crackers may do damage, like deleting files or encrypting them for ransomware.

By the 1990s, viruses had become a serious problem, especially among Windows users. The production of special antivirus software became an industry in itself, until it finally became a default part of the operating system.

See boot virus, phage. Compare back door. See also Unix conspiracy.

[Jargon File]

Last updated: 2024-01-21

Nearby terms:

Virtual Telecommunications Access Methodvirusvirusesvisible bell

Try this search on Wikipedia, Wiktionary, Google, OneLook.