A new variant of KoobFace, a dangerous kind of worm, has been attacking Facebook users this week. The virus can spread rapidly because they move through messages which appear to come from your pals.

So don’t be enticed by those sweet messages.

Those “friends” you have on Facebook might not actually be your friends. In fact, some of them might be scammers trying to infect your computer with this virus.

Even before the first virus struck, Kaspersky Lab the one who discovered the virus, had forecast that there would be a proliferation of these problems.

According to them, messages and comments on MySpace and Facebook include links to http://youtube.[skip].pl. If the user clicks on this link, s/he is redirected to http://youtube.[skip].ru, a site which purportedly contains a video clip. If the user tries to watch it, a message appears saying that s/he needs the latest version of Flash Player in order to watch the clip. However, instead of the latest version of Flash Player, a file called codecsetup.exe is downloaded to the victim machine; this file is also a network worm. The result is that users who have come to the site via Facebook will have the MySpace worm downloaded to their machines, and vice versa.

This attack on the world’s most popular social networking site and its 120 million users comes just weeks after Facebook won an $873 million lawsuit against several people accused of hacking user accounts and spreading spam.