viruses

A submicroscopic, non-cellular structure consisting of a core of DNA or RNA surrounded by a protein coat, that requires a living host cell to replicate, and often causes disease in the host organism.

A disease caused by these organisms.

“He caught a virus and had to stay home from school.”

Venom, as produced by a poisonous animal etc.

A type of malware which can covertly transmit itself between computers via networks (especially the Internet) or removable storage such as disks, often causing damage to systems and data; also computer virus.

Any type of malware.