Named after the Trojan horse of Greek mythology, a trojan is a program that claims to be one thing but is, in fact, another. A trojan horse is not a virus per se, but it may carry them. For example, many people consider Kazaa, the music sharing software, to be a trojan horse, because it often carries with it a bunch of spyware. There are trojans that claim to be patches for a problem, often arriving in email, which are in fact spyware and virus installers.« Back to Glossary Index
Leo A. Notenboom has been playing with computers since he was required to take a programming class in 1976. An 18 year career as a programmer at Microsoft soon followed. After "retiring" in 2001, Leo started Ask Leo! in 2003 as a place for answers to common computer and technical questions. More about Leo.