Yesterday my account was hacked @ 3:38 PM GMT.
Hacker managed to change my account's e-mail id & then the password.
I noticed it at 3:45 PM GMT & got my account locked using the link the forum sent me on my e-mail id along with e-mail change notification.
That gives the hacker a 7 minute window in which he could have used your account to PM users trying to scam them. I don't think it's very likely, but if you sign a message from an address posted anywhere, I'll tag the account just to be sure.