5. Trojan Horse is a program that does something undocumented which the programmer intended, but that the user would not approve of if he knew about it According to some people, a virus is a particular case of a Trojan Horse, namely one that is able to spread to other programs A simple example of a trojan horse would be a program named "waterfalls.scr" claiming to be a free waterfall screensaver which, when run, instead would allow access to the user's computer remotely. About trojan horse