security> (Coined by MIT-hacker-turned-NsA-spook Dan Edwards) A malicious, security-breaking program that is disguised assomething benign, such as a directory lister, archiver, game, or (in one notorious 1990 case on the Mac) a program to find and destroy viruses! A Trojan horse issimilar to a back door. see also RFC 1135, worm, phage, mockingbird. [Jargon File] (1995-03-21)