Virus experts at Finnish firm F-Secure issued a warning on Monday over a worm that spreads via the instant messaging function in VoIP software Skype.

The W32/Pykse.A worm spreads by sending a message with a malware link to all online friends in Skype’s contact list by exploiting the Skype API.

Sneakily, the worm will also set the infected Skype user’s status to DND (Do Not Disturb), which means the application will not actively notify the user of calls or messages to reduce the chance of contacts questioning the validity of the link.

Anyone who clicks on the link will be shown a picture of a naked woman to disguise the infection going on in the background.

Antivirus firms including F-Secure have already released an update to catch this virus.