What is this thing?

[dope1314]

So i was playing CoD mw2 and all of the sudden some dude runs a hack, boom all my stuff is back to 0 and like 20+ game files gets corrupted. So everytiem i try to join a game i get into the hackers lobby. So i wonder what is this and what can be done to prevent this in the future?

[Mustafapi]

Re-install the game to get rid of the corrupted files and I don't this is avoidable in the future just back up your multiplayer game files every now and then.