http://www.wowace.com/
http://forums.wow-europe.com/thread....30404058&sid=1
Taken from the thread: It's what they call a
Man In the Middle attack:
There's usually a keylogger lurking on your computer that relays the necessary information to the hacker, and they can get past your authenticator and hack into your account. Essentially, they intercept the message before it gets to its destination, use the authenticator key, and send the WoW client a fake key so your login fails.
Check the links above. Wowace has a main article on the front page about this, and the thread in the WoW forums is very useful.
Scan your computers, too.
The only upside to this is they only get one authenticator code from your computer, and your authenticator changes codes every 30 seconds.