I think I've been hacked

Act fast, in this order. Do not confirm anything on your phone until it is sorted out.

1. 1. Confirm nothing

   On your phone, do not accept or confirm any offer, even if it seems to come from a friend.

2. 2. Revoke your Steam API key

   Open the Steam API key page and revoke any key you did not create yourself.

   Open the Steam API key page

3. 3. Change your Steam password

   From Steam only, never from a link you received.

   Steam help

4. 4. Deauthorise other devices

   In the Steam Guard settings, deauthorise all other signed-in devices.

   Manage Steam Guard

5. 5. Cancel suspicious offers

   Check your sent offers and cancel the ones you do not recognise.

   My sent offers on Steam

6. 6. Contact Steam Support

   If items were stolen, open a ticket with Steam's official support.

   Steam Support