A worm is a program that duplicates itself from one directory,
drive, computer or network to another. Most worms send
themselves through e-mail and many have mass-mailing functions,
which allow them to mail themselves to every address in a
particular mailbox. Another popular method of transmission for
worms is through Local Area Networks. A few can even come
through instant messangers. Unlike a virus a worm is a self-
contained program and does not need to attach itself to an
executable files, though some worms have a viral component that
infects files. As they are executable programs, they can become
infected with viruses and all "descendants" of that copy of the
worm maybe infected with the virus and have the ability to
infect files on other computers that they spread to when they
are run. As with viruses, worms come in many types. The most
common method of categorization is how they spread. Some worms
may have more than one method of spreading. Email worms spread
through email messages. Essentially, an emai