Windows 7: The botnet ecosystem.

With the appearance of botnets, criminal gangs have gained access to millions of infected computers and the number of cybercrimes committed has risen sharply. Although the majority of Internet users understand that zombie networks pose a serious threat, many do not know how or why botnets are created and maintained.
Botnets act as a key link in the cybercrime chain. It doesn't take any real technical skill to understand what role they play: cybercriminals do business with each other via the Internet and visiting the sites they use provides a wealth of information.

Remember gang, you, and not your Anti Virus, are the first line of defense against all evil out there.