worm

(1) A destructive program that replicates itself internally or throughout the network. A worm can do damage by sheer volume, consuming internal storage and memory resources or by exhausting network bandwidth. It can also deposit Trojans that turn every computer in the network into zombies for spam, denial of service (DOS) or some other malicious attack. Very often, the terms "worm" and "virus" are used synonymously; however, worm implies automatic reproduction. See virus, logic bomb, smartphone virus, denial-of-service attack, spam, Stuxnet, Worm.ExploreZip virus and Morris worm.

(2) (worm) A program that moves through a network and deposits data at each node for diagnostic purposes. A worm may cause idle computers to share some of the processing workload. See ethical worm.

(3) (WORM) (Write Once Read Many) A magnetic tape format that can prevent recorded files from being erased or rewritten. See LTO.

(4) (WORM) (Write Once Read Many) There are two kinds of optical drive technologies that prevent files from being rewritten. The traditional ablative WORM makes a permanent change in the recording material. Continuous composite write (CCW) is a WORM mode in a normally rewritable magneto-optical (MO) cartridge. The drive's firmware ensures that recorded areas on the medium are not rewritten. See optical disc and MDISC.