This is a post i put in the Cod4 MW2 PC forum and was asked to pop it over here for you folks to make yourselves aware of.
Some information has come to light that exploits are spreading, virus like, through IWNet.
IWNet is supposed to create an exploit free envonment for players to play. Already the Rocket Launcher/Human Bomb exploit has made a nuisance of itself. Now there is an unlimited ammo exploit making the rounds.
Horrorfyingly, this exploit can spread from one console to another just by joining a game hosted by someone who has the exploit. It spreads like a virus from one machine to the next upon contact and if you are unlucky enough to make contact with an infected system, you have no choice, you have the exploit.
More info:
Steam Users' Forums - View Single Post - A virus is quickly making the 360 version unplayable
ModernWarfail2 – The biggest FAIL in PC FPS gaming history Blog Archive Unlimited Ammo ‘virus’ infects other Xbox 360 players like an STD
Just for you folks that may have PS3's and 360's i have read there is a band aid solution, disconnect from the net and turn off your console. It sits in the cache and isn't permanent.