Whether or not you know this already, I've been hacked by someone on Steam. My account is "Avery / Aezel" with a Klonoa avatar. The hacker stole my account after posing as a fake admin. I mistakenly contacted him by Steam handle thinking he was a real admin after I was told by another hijacked account that I was being reported for item duplication, and when I wouldn't give him $500 I didn't have, he locked me out of my Steam account and stole it before trying to forcibly steal money out of my bank account.

I need as much information as I can get from this guy. He will try to interact with you because he will be out for your accounts. Don't let him trap you. Instead, your best bet is using fake accounts and virtual machines. The goal is to fish information out of this guy, bait him with the promise of money and trap him in hopes of getting my account back and turning him in to the proper authorities. Take screenshots, ask questions, but DO NOT give him your information.

If you can't do any of this, then just don't interact with him. Either way, BE CAREFUL.