A Worm is a virus-like software application which spreads itself to other computers. Worms send themselves out to email addresses collected from the infected PC. Worms are known to mutate and they usually carry a destructive payload.
Virus-like program that spreads automatically to other computers, by sending itself out by email or by any other means. A program that propagates itself by attacking other machines and copying itself to the affected machine. Both worms and viruses are self-replicating code that travels from machine to machine by various means. Both worms and viruses have, as their first objective, merely propagation. Both can be destructive, depending on what payload, if any, they have been given. But there are some differences: worms may replace files, but do not insert themselves into files. In contrast, viruses insert themselves in files, but do not replace them.
