Schwick, Wow Europe MVP, reports a critical event where the Wow Background Downloader and Wow Patch executables are targeted by certain Anti-Virus software as trojans after a recent definition update. Schwick’s thread compiles a list of Anti-Virus software and solutions. Do not delete the files. In the event this happens, do not play World of Warcraft until new definition updates for your Anti-Virus are available. This is what a Blizzard Rep from Tech Support commented:
Torzelyn: “We’re investigating this at the moment. It seems some anti-virus programs were updated last night with new definitions, and they’re now identifying the Background Downloader and some patch files as a trojan. We’re trying to examine this further here and we’ll let you know as we have any information.
I think the main thing I need to make sure you all know here is; don’t panic. It’s not looking like it’s a trojan, just a false positive. Don’t worry about your account being hacked or compromised from this particular event, but don’t try the game until the anti virus program ok’s it. We need to be absolutely sure about this before you start using your game again.
Just make sure you keep checking the manufacturer of your anti-virus’s website for definitions files, hopefully you should get one soon which will ‘pass’ these files.”