In Game Error

Hi, I'm here to complain about me getting an error while having a... lets say a "good game". And it says :

Hack tool has been detected (1) (0:4:0:0)

And I'm not even hacking. I after getting that error i still can log it in.

here's a photo of it :

http://imageshack.us/photo/my-images/23/cferror.png/

-Thanks!