A new computer Trojan disguised as a media file has been described by security experts as the most significant malware outbreak in three years.
McAfee Avert Labs has discovered more than 360,000 detections of a Trojan horse which hides behind fake music and video files on P2P networks such as Limewire and eDonkey.
When someone attempts to load one of these MP3 and MPG files, they don't get the music or video they were hoping for but are instead instructed to download a file named PLAY_MP3.exe. If you agree to download and run PLAY_MP3.exw, it serves the computer with adware.
Craig Schmugar, a researcher with McAfee, said: "This is one of the most prevalent pieces of malware in the last three years. We have never before had a threat this significant that arrives as a media file."
"In the end you're left with a fake MP3 file taking up space, a worthless MP3 player, adware that claims not only to not display pop-ups but also to block them, and more adware that successfully displays pop-up and pop-under ads."
According to McAfee, it has rated the threat "medium" risk, the highest risk rating given to a threat since 2005.
MP3 trojan doing the rounds