Worm

A worm is type of malware that self-replicates and distributes copies of itself to its network. These independent virtual viruses spread through the Internet, break into computers, and replicate without intervention from and unbeknownst to computer users.

Internet worms can be included in any type of virus, script or program. These worms typically infect systems by exploiting bugs or vulnerabilities that can often be found in legitimate software. Unlike Trojans or other viruses that require user intervention to spread, Internet worms can spread on their own. This makes them extremely dangerous.