Security experts have warned Skype users that new malware similar to the infamous Koobface worm that caused havoc on Facebook is now targeting the popular IP telephony service.

Trend Micro said that it detected the Koobface-like variant as TROJ_VILSEL.EA, a piece of malware designed to steal contact lists, phone numbers, locations and other information that forms part of a Skype profile.

"It is also capable of using Skype's built-in instant messaging capability to send links to people on the affected user's contact list," wrote Jonathan Leopando, a member of Trend's technical communications team, on the Trend Micro blog. "These links all go to affected domains with copies of TROJ_VILSEL.EA."

However, Leopando explained that the new worm is not actually a member of the Koobface family.

"Both the malicious code and network behaviour differ from previously known Koobface variants. It would not be a great surprise, however, if the actual Koobface cyber criminals produce their own variant with this behaviour," he said.

"This development only highlights the ingenuity of cyber criminals in going after targets using tried-and-tested ways to spread their malicious creations."