McAfee is warning users to be wary of a new piece of "malware" which has affected around half a million computers in just seven days.
The software pretends to be an ordinary media download, such as the recent St Trinian's remake, or a Girls Aloud song, however, once activated the software asks the user to download a codec to play the supposed media file. Once run, a bundle of adware is installed bombarding the user with pop-ups.

McAfee claims the malware is principally being distributed across the eDonkey and LimeWire file-sharing networks, and is the largest outbreak it has witnessed in three years.

The company has called the attack "relatively benign" and suggests the culprit is probably some ad-affiliated scheme looking to make money from careless clicks.

Nonetheless the company says it remains concerned about another party using the same technique to spread more malicious software in the future.