Koobface tricks social networkers into downloading malicious malware onto their PC. Users receive messages that look as if they're videos. Often they say something like "you look funny". When the user clicks to see the video, he is taken to a new website and asked to download special software in order to see the video.
That software is malicious and once installed on a PC, the Trojan will direct users to hoax search engines and other websites, putting them at risk of ID theft.
According to the security company, Koobface has been identified on Bebo and could even spread to other social networking sites including MySpace and Friendster. ScanSafe also claims that the virus accounts for one per cent of all its blocked malware.
"Those who avoid promiscuous 'friending' on social networking sites will be least likely to encounter a Koobface type threat," said Mary Landesman, senior security researcher, at ScanSafe.