someone being in my acc that unfriended everybody

[Norlium]

I first thought it's bug that I don't see my friends show up, than I find out that they have been deleted manually.

I look at my login history and few days ago there have been logins in Buchurest, Amsterdam, Tokyo even tho I have Steam Guard and all

Watched some video about this unfriend thing, it's sort of attack so that your friends will never see your new name once the damage is done.

My question is, what is there to do to unlogin these devices and keep my account safe only for myself?

[Dan5000]

It is 100% that someone else is on your account, can't happen otherwise.

Follow all these instructions, otherwise you can't be sure that no one is still on your account:

1. Scan for malware https://www.malwarebytes.com/
2. Check that the email and phone number on the Steam account are still yours.
3. Deauthorize all other devices https://store.steampowered.com/twofactor/manage
4. Change passwords from a trusted/clean device.
5. Generate new backup codes for your Mobile App https://store.steampowered.com/twofactor/manage
6. Revoke the API key https://steamcommunity.com/dev/apikey (there should be nothing in the APIKEY)

There are only 3 ways for others to get into your account:

1. You either got infected and had malware steal your active session, which means steam thinks it is your own doing. (Or you logged in on another infected machine)

2. You entered your login + Steam Guard code somewhere you were not supposed to. (Scanning the QR code to login does the same)

3. Someone else has/had physical access to your devices. (Or you forgot to logout after being in an internet café etc.)

You can't deny all 3 of these, it's impossible to get into your account otherwise.

Stolen wallet or items that way will not be refunded, as it is the users responsibility to make sure their accounts are safe.

[Rex]

If you need help with Account Security or Recovery, please contact Steam Support.