(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.
WORM Cartridges
Large-format 12-14" WORM drives use the ablative technology; however, magneto-optic (MO) drives have firmware that turns MO media into write-once disks.