Valve Corporation has shut down their forums on Steam after an attack on Sunday. Today, company head Gabe Newell says credit card and other personal information may have been compromised during the attack.

Hackers forced the Steam Forums to shut down as a security measure after the attack and subsequent defacing of it on Sunday.

Valve does not have evidence of the data theft as of yet, nor can they verify that the encrypted information has been cracked. However, Valve has recommended vigilance and the changing of passwords, especially if they’re the same ones you use for everything else. The rest of Steam is still in operation, and users are required to change their forum passwords when the forums reopen.

So, if you’re paranoid like me, change your passwords for your account on Steam and monitor activity on your credit card.