4.1.1 Worms

A worm is a program that does the following:

• Seeks out for potential machines to infect via network ``exploration''.
• Infects (execute on) a victim computer remotely via some form of network connection.
• Installs itself on the victim machine, and start the first step all over again.

The list above only describes the propagation method of a worm, but it does not include any mentioning of the ``payload'' of a worm. In other words, a worm can perform all kinds of harmful operations once it starts execution on a victim machine.

We'll separate the discussion of ``payload'' into its own topic.