SpyBot is a very dangerous worm. It uses many ways to provide a hacker with remote access of an infected computer. Once SpyBot gets on a machine, it rings an IRC server and waits for instructions from an attacker. The later can execute commands then and gain control of the compromised system. SpyBot (a.k.a. W32.Spybot.Worm) infection results adware pop-ups, joining botnets, identity theft and loss of other sensitive data. The worst thing about W32.Spybot.Worm is its ability to hide its presence; people may not notice SpyBot aboard a computer unless reputable anti-spyware scan is used. SpyBot spreads via mIRC, Kazaa p2p download manager and free downloads on the Internet. Do not take SpyBot as Spybot Search and Destroy. Spybot Search and Destroy is anti-spyware and it is not a threat to your computer; but SpyBot worm is a very dangerous infection and it should be deleted as soon as possible.

Source: http://www.2-viruses.com/remove-spybot