Accounts are phished not hacked.

You gave away all your account details.

The account name, the password and the KEY to the door, the Steam Guard Mobile code giving them access to the account.

How? by either logging into a known scam site or sites, tailored malware on your PC, the vote for my team scam, you have a pending ban scam on Discord, free knife click the link etc.

How does Steam (a program) know it is not you when all the account details are correct? It doesn't, therefore any action taken on your account is seen as you doing said actions.

The alternative is not plausible:

1) Someone would have to "GUESS" your account name from "millions of possible combinations".

2) Next they would have to "GUESS" your password from "millions of possible combinations" and then match it to your account name with "millions of possible combinations".

3) And finally they would have to "GUESS" the Steam Guard Mobile code "which changes every 30 seconds" to match both your account name and password to then have access your account.

Steam Account Recovery

It is possible to recover a stolen Steam account. You don't need access to the email, phone or password currently tied to the stolen account for this to work.

The recovery process allows you to contact Steam Support to provide proof of ownership.

Follow this guide to recover your account:

https://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=3456188107

Support articles about account recovery:

Recovering a Stolen or Hijacked Steam Account

Providing Proof of Ownership

Link from the guide to start the recovery process:

https://psteamhelp.yuanyoumao.com/en/wizard/HelpWithLoginInfo?accountsearch=1&issueid=408&reset=1

No need to create more threads, one is enough.

https://psteamcommunity.yuanyoumao.com/discussions/forum/1/597413835511733191/