Your CD-Key was leaked and was also used to cheat that produced a valid Game Hack violation from Evenbalance.
http://www.pbbans.com/mbi-viewban-ded8b88a-vb159521.html
All I can say is make sure you run a virus scan of your PC to see if there are any trojans, virus's, keyloggers, etc. Somehow your key was stolen. The only thing you can do is go buy a new game from a well known retailer and keep your CD-key private and not let anyone play on your PC.