There is a huge problem with Valve Anti-Cheat system at the moment. It seems that they have enabled a brand new manual rule that triggers a VAC ban on certain Steam accounts. If you launch Steam on Linux with an account name (OS account, not Steam account!) that contains “Catbot” you WILL be banned on Steam. Permanently.
Why does that even happen?
It’s because of a certain Team Fortress 2 farming bots that got really popular lately, here’s the explanation from reddit:
Some guy makes a bunch of bots named like “Catbot #47” and sends them out onto Casual servers in TF2, they follow a set path based on the map and have aimbot. They’re honestly really well made, and the way they’re getting banned is that Steam checks the program’s username on its Linux partition (not the Steam account’s username). He’s already changed the code to randomize the Linux username and sent them back out.
So as you see the farming/hacking is working just fine once more because someone already fix their “security measures”. Apparently that was intentional behavior by VAC team and according to them it’s a feature… not a bug (if you believe the guy from Github):
Good day, I’ve received word from the VAC team that this is intentional and not open for discussion on Github.
In general VAC issues are not handled on Github in any capacity and further issue reports on this may result in being banned from the Valve Software issue trackers.
If any of you use the name catbot for some odd fucking reason (because why the fuck not, right?) watch out for that stupid rule and don’t get yourself banned. VAC doesn’t make mistakes my ass. This reddit post sums up the situation perfectly: