I mentioned earlier that there is a new trojan virus that can even compromise World of Warcraft accounts with an Authenticator. There were not that much details in the news.
But now a forum moderator of Blizzard came up with some more news about the trojan. It seems that Blizzard found out that the trojan is coded into a fake but working Curse client. Don´t worry this fake Curse client is has not been distributed by the original Curse Website which is visited by many World of Warcraft players. It´s rather so that a faked Curse website copy popped up on major search engines and that was sadly the way how the fake client has been distributed.
You can find out more details and how to remove the trojan in the WoW forum, in case you are affected.
Diary of Dennis 
Thanks for informing us, I just had my account banned due to irregular activity logging into the website :S I know, very strange but now I wont have to worry about any possible Trojan getting me hacked / banned also 🙂
I had this sometimes in the past too. The IP protect while login is a great second security layer by Blizzard. If I got this email, I usually still change the password to be on the safe side. If there is no trojan, then everything is just ok with changing the password I guess.