The largest trojan media file outbreak for three years has been reported by security company McAfee, with up to half a million victims so far. The fake file hasbeen distributed on file-sharing network Limewire and others in various guises: sometimes it’s a music file, at other times it could be a video or movie. However it’s sent, the results are the same. As soon as the user runs it, the trojan, Downloader-UA.h, installs adware that plagues the user’s computer with pop-up ads, and whichcould also seriously compromise the security of the machine. Whoever did it has been very thorough and clever. The file is written in several different languages and comes with a number ofdifferent titles, posing as popular music tracks such as “girls aloud st trinnians.mp3” or “pull over levert.mp3,” or it might offer the full version of a new movie or porn.Whatever the name, when it’s downloaded, the user is as to install a codec, PLAY_mp3.exe, in order to play the media file. The adware is in that codec. McAfee says that the file has beenfound on roughly 500,000 of the computers that report to them whenever malware is downloaded, but only about 10% of that number have actually installed the codec. Other companies have alsoreported the file, but not in such large numbers.