Is there a particular reason why c:\users\public\games\worldofwarcraft\blizzarddownloader.exe is coming up as malware? Anyone know? I ran a malware scan prior to launching the game, and AVG picked this up after opening the game.
As others have mentioned, Malware, chances are that it's a false positive. To be safe I would recommend manually delete the file, run the repair tool and then run a virus scan.