Net-Worm.Win32.Koobface attacks Facebook and MySpace accounts. There four variants so far, and there may well be more to come.
The worm uses a pretty simple approach - a link to a 'video', and then, when the user tries to watch it, s/he gets a message saying they need to update their Flash Player. It's an approach we're seeing a lot at the moment; download the 'Flash Player' file and there's new malware on your machine.
Of course, this isn't the first malware for Facebook or MySpace. There has been earlier variants of this worm which attack MySpace, but not Facebook. The virus writers behind Koobface are clearly trying to maximize the number of victims - the more there are, the bigger the botnet is going to be.
The guys behind Koobface are also linked to the 'fake antivirus' programs XP Antivirus and Antivirus2009 which are actually spyware. Installers for these spyware programs have been detected which also contain the worm code. And Trojan-Downloader.Win32.Fraudload, which was being used to download XP Antivirus etc. is now being used to download the worm files.
The result is a double whammy: in addition to being infected by the worm and herded into a botnet, victim machines are also going to get hit by one of these nasty pieces of spyware.
So watch out!
There are a number of good antivirus program out there that can protect you. One highly aclaimed one is Kaspersky Internet Security 2009. It is well worth checking out.
Click here for more info.