Fake joke worm wriggles through Facebook

Shifty sorts have created a new worm which spread rapidly on Facebook on Friday.

The malware, for now at least, does nothing more malicious than posting a message on an infected user's Facebook wall that point to a site called fbhole.com. Nonetheless, the speed of its spread on the social networking site has net security experts worried.

The message that the worm posts takes the form
:

try not to laugh xD http://www.fbhole. com/omg/allow.php?s=a&r=[random number]

Net security firm F-Secure reports that following the link takes a surfer to a fake error message. Clicking anywhere on this page fires up a script that posts the same message on a user's Facebook wall, continuing the spread of the malware.

As a search via youropenbook.org illustrates, the worm spread like wildfire on Friday afternoon.

The fbhole.com domain associated with the attack was only registered on Thursday. It points to an IP address in Czech Republic, shared by another Czech site called ironbrain.net.

Mikko Hypponen, chief research officer at F-Secure, tracked down contacts for the ironbrain.net domain on Friday afternoon, and confronted them with questions over his suspected involvement or complicity in the spread of the fbhole.com worm. The unnamed person hung up the phone on Hypponen.

The fhhole.com domain at the centre of the security flap was shut down just seconds after the end of this conversation. Minutes later the site was back up again, redirecting traffic to a harmless web game.

More on the attack - including screenshots - can be found in a blog post by F-Secure here. ®