**4.6 Worms**

Computer worms are fragments of malicious software that reproduce swiftly and blow out from one computer to another through its contacts, again spreading to the contacts of these other computers and so on and reaching out to a large number of systems in no time. Captivatingly, worms are prepared for spreading by exploiting software vulnerabilities. Worms display unwanted advertisements. It uses up tremendous CPU time and network bandwidth in this process thereby denying access to the systems or network of the victim, creating chaos and trust issues on a communication network.
