Valve was able to recover my Steam account. Unfortunately the miscreant has deleted all of my friends so I am now isolated from my community.
I have also discovered that everyone of my friends was spammed with a phishing site URL. This suggests there was a serious effort to steal account credentials.
The damage is severe as I had many developers as contacts in the community and we worked many times together on game issues. I also get a lot of games from the developers for review.
The name on the account user was Eldar Jarakhov (Эльдар Джарахов), Russian Federation. This name is that of a popular Russian Entertainer so it’s obvious the miscreant was not that stupid.
The Irkutskaya Oblast is in Siberia in eastern Russia. Zheleznodorozhnyy is known to be in northern Kazakhstan. The maps are likely not all that up to date. Steam logs show it as RU but satellites show it as very a remote area.
It appears that some shadow group of hackers is trying to steal Steam accounts and my account is rich with games. I get many games each month from publishers.
The person had interacted entirely with Russian speaking persons. It’s not clear what is likely to be happening next.
We noticed the player was playing CS:GO and he made a large number of new achievements. Little consolation for deleting my friends list.
The damage from the loss of my friends list is incurable and destructive. So now I am recommending everyone change their Steam passwords immediately.
I also discovered almost all of my screenshots disappeared. I used to have hundreds of them. Curious as some remained. I was using Steam as a content delivery network for screenshots which made it a lot easier to use wordpress on Azure who is very limited with storage. Even WordPress is dramatically more generous with storage.