Just giving you a heads up, The account that you posted on saying he was trying to steal your account, It's not the owner that's doing it.

He got his account phished, I also fell for the same phishing attack and also lost control of my account.

Luckily I was able to warn friends offline about it so the phisher didn't get very far besides messaging 3 buddies, All were told by me under no circumstance to speak to the "steam admin" and to close the window.