This document discusses computer viruses and how they differ from Trojans, worms, and hoaxes. Solution The term virus is often used as a generic reference to any malicious code that is not, in fact, a true computer virus. This document discusses viruses, Trojans, worms, and hoaxes and ways to prevent them. What is a virus? A computer virus is a small program written to alter the way a computer operates, without the permission or knowledge of the user. A virus must meet two criteria: It must execute itself. It will often place its own code in the path of execution of another program. It must replicate itself. For example, it may replace other executable files with a copy of the virus infected file. Viruses can infect desktop computers and network servers alike. Some viruses are programmed to damage the computer by damaging programs, deleting files, or reformatting the hard disk. Others are not designed to do any damage, but simply to replicate themselves and ...