Viruses, Trojan Horses, and Worms - Computer Definitions


virus - a virus is a destructive computer program that quickly replicates and sends itself through a network of connected computers. The virus is written to alter the settings of the computer that it infects.

trojan - a trojan horse is a malicious, security-breaking program that is disguised as something benign, such as a screen saver, a game, or some other valuable program. when you open a trojan horse
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worm - a worm is a program or algorithm that replicates itself over a computer network and usually performs malicious actions, such as using up the computer's resources and possibly shutting the system down
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