A new variant of the Koobface worm has returned to menace users of Facebook.
As before, the malware generates messages to friends of infected users on the social networking website. These messages direct the unwary into visiting websites that supposedly offer video clips. Would-be marks are told they need the latest copy of Adobe Flash to view this content and are prompted to download a file, which actually contains the worm's payload.
If the code executes on a vulnerable Windows PC the user gets infected. The worm's lifecycle then begins anew, ready to target their Facebook friends too.
The malware was first spotted in late July. Like a nasty case of herpes it flared up again last week, months after the initial attack.
The latest variant of the malware typically comes in a less salacious package. The first wave of infections came with messages such as "Paris Hilton Tosses Dwarf On The Street" whereas the latest variant is more likely to pose as "secret video by Tom" or some such. The latest Koobface variant is programmed to hijack search queries and divert infected users to bogus sites, benefiting crooks through related ad hijacking and click fraud in the process.
Facebook's advice for dealing with the worm can be found here. The social networking utility is in the process of purging spammed links to the malware from its systems, reports McAfee, which has a full write-up of the threat here. ®