Antivirus companies have unearthed a computer worm that hides behind an image of naked people.
According to antivirus company Sophos, the naughty New Year photo message contains a mass-mailing worm, dubbed Wurmark-D, that is programmed to disable security software on host computers and send itself to email addresses stored there.
"Once activated, this worm will harvest your computer hunting for other email addresses to send itself to and try and turn off antivirus software," said Graham Cluley, senior technology consultant for Sophos.
"Anyone who forgets to exercise caution before running this unsolicited email attachment could be in for a rude awakening. People coming into work after a long holiday, and possibly facing a few thousand emails in their inbox, should be careful not to fall for the confidence tricks often used by computer viruses."
The Wurmark-D worm travels as an attachment to an email that claims to include some amusing content. When the file is opened, the worm displays a graphic image of nude men and women contorting to form the words "HAPPY NEW YEAR". But at the same time, the worm secretly installs itself behind the scenes, and forwards itself to other computers.
Sophos said that typical Wurmark-D worm emails had the following characteristics:
Subject: "HAPPY NEW YEAR!!!
Message body: All the best in new year from our family here is a litle attachment to make you smile in new year email me back haha...
The worm has only caused a small number of reports.
Last year a virus writer sent emails promising photos of a blonde, 21-year-old go-go dancer, and the email attachments turned out to be a mass-mailing variant of the Sober worm.