My account has been taken over, please help!

[Macewind]

Over the past 2 days someone has been using my account to make marketplace trades. Last night there were hundreds of review awards and community profile awards given out from my account. Then tonight my account started messaging friends with a dodgy link. One friend clicked it and now has had his account stolen. His email and passwords changed, everything.
I've got 2fa enabled so I'm not sure how this has happened. I've ran malwarebytes and changed my passwords. I don't know what else to do!

[rawWwRrr]

The list:

Steps to take NOW:
1. Scan for malware https://www.malwarebytes.com/
2. Deauthorize all other devices https://store.steampowered.com/twofactor/manage
3. Change passwords from a clean computer
4. Generate new backup codes for your Mobile App https://store.steampowered.com/twofactor/manage
5. Revoke the API key https://steamcommunity.com/dev/apikey (there should be nothing in the APIKEY)

[Macewind]

Done all of that, the api link wants me to register for a new apikey so I'm guessing that's empty and fine?

[The Giving One]

Opprinnelig skrevet av Macewind:

I've got 2fa enabled so I'm not sure how this has happened.

Giving away the codes on a shady third party site, or fake login page is the most common cause.

Only way they could get in is either with your other device in hand, or to get the codes, so the codes were the leak, surely.

[Macewind]

No idea, I've not put the codes anywhere. I've also had unauthorised purchases made from my amazon account last week and am wondering if that's related. I downloaded a load of msdos games last week so suspect a dodgy file has slipped past the antivirus

[cSg|mc-Hotsauce]

Opprinnelig skrevet av Macewind:

I downloaded a load of msdos games last week so suspect a dodgy file has slipped past the antivirus

Probably.