users are being warned to watch out for a new computer virus targeting popular social networking sites in the run up to Christmas.
Sky News has been told that Facebook users are most at risk from a variant of the Koobface virus, which has been disguised as a Festive greetings video, hosted on a YouTube site.
Security experts say the new virus is “particularly nasty” and compels its victims to participate manually in creating a new Facebook account to help spread the worm.
In previous years, variations of this virus have caused chaos across the web.
But internet security experts believe the new worm is likely to prove particularly effective in fooling users, because of the growing number of people who now opt to send out electronic greetings cards.