What is "koobface"

Koobface is a network worm that attacks Microsoft Windows, Mac OS X, and Linux platforms. This worm originally targeted users of networking websites like Facebook, Skype, Yahoo Messenger, and email websites such as GMail, Yahoo Mail, and AOL Mail. It also targets other networking websites, such as MySpace, Twitter, and it can infect other devices on the same local network. Koobface is also used by technical support scammers to fraudulently claim to their intended victims that they have a virus on their computer by using fake popups and using built-in windows programs.