This worm, dubbed Wurmark-F, travels as an e-mail attachment and affects systems running Microsoft Windows. When opened, it displays a photo of a man "gurning"--a British tradition of pulling silly faces.
Sophos reported that when run, the worm installs a Trojan that allows hackers to take control of infected computers and capture information.
"At first glance, some may think this worm is harmless and be amused by its graphical payload--but it has the sinister intention of handing over control of your PC to remote hackers," said Graham Cluley, senior technology consultant for Sophos. "If you attach a new, unpatched computer to the Internet, unprotected by proper firewalls and up-to-date antivirus software, then it can easily be under the control of hackers within 10 minutes."
Users were confronted with another abusive worm earlier this week that sang the words "you are an idiot" at its victims.
Dan Ilett of ZDNet UK reported from London.