McAfee Avert Labs has reported the most significant malware outbreak in three years with more than 500,000 detections of a Trojan horse masquerading as a media file.Since Friday May 2nd, more than half a million instances of the Trojan have been detected on consumer PCs running. The malicious MP3 music or MPEG video files have appeared on popular file-sharing services such as Limewire and eDon