Trilight Zone

[digital8]

Computer Worm a program that resides in the active memory of a computer and duplicates itself; for example, from one disk drive to another, or by copying itself using email or another transport mechanism. Once the worm has infected your system, it may automatically send out emails containing more copies of the virus using the address book in your email program.
The worm may do damage and compromise the security of the computer. It may arrive in the form of a joke program or software of some sort. Worms are very similar to viruses in that they are computer programs that replicate themselves and that often, but not always, contain some functionality that will interfere with the normal use of a computer or a program.
Worms use facilities of an operating system that are meant to be automatic and invisible to the user. It is common for worms to be noticed only when their uncontrolled replication consumes system resources, slowing or halting other tasks. A new class of worm, such as Worm.ExploreZip, resides in your system's memory and self-replicates, but also contains a malicious payload.
The difference is that unlike viruses, worms exist as separate entities; they do not attach themselves to other files or programs. A worm can spread itself automatically over the network from one computer to the next. Worms take advantage of automatic file sending and receiving features found on many computers. It is worms that have caused the greatest disruption and destruction around the world because of their ability to spread independently, without a requirement for a file to be run.