Worm (computer worm)
Definition
A computer worm is malware that automatically spreads across networks without user interaction. Unlike a virus, a worm does not need a host file.
Worms spread through network vulnerabilities, email attachments, or shared network drives. Because they require no user interaction, they can spread extremely rapidly.
Famous worms: WannaCry (2017) spread via EternalBlue affecting 200,000 systems in 150 countries.