Santa Clara (CA) - After almost three years of most Internet dangers coming from phishing e-mails, misleading "You’ve won" websites and fake anti-spam/anti-spyware tools, a new trojan has appeared and has caused almost half a million infections.

Bear in mind that 500.000 infections were stopped by McAffee tools, but this is by no means the final number of potential infections, and can give you a rough idea what happened on computers that were not protected by malware-stopping applications.

McAfee reported that Downloader-UA.h trojan is present in hundreds of media files that were uploaded to file-swapping services during the last weekend. Limewire and eDonkey were the most affected ones, so caution is needed if you use those services. According to Avert Labs, files are named differently in multiple languages and different sizes, so they look legit. Files are all coming in MPEG or MP3 format, and McAfee Avert Labs released names of some media files:

PLAY_MP3.exe
preview-t-3545425-adult.mpg
preview-t-3545425-changing times earth wind .mp3
preview-t-3545425-girls aloud st trinnians.mp3
preview-t-3545425-jij bent zo jeroen van den.mp3
t-3545425-lion king portugues.mpg
t-3545425-los padres de ella.mpg

You can see more details on McAffee Alert Lab blog. Trojan Downloader-UA.h received a "medium" risk, raising the global alert level to "elevated". If you use file-sharing networks, watch out for these files.