I recently saw the game called "Bongo Cat" on Steam which monitors yours keystrokes and accordingly plays the bongo drums. I saw that it was not working properly on Wayland because it does not allow the game to record keystrokes from other apps.
This got me thinking; how does ~~Steam~~ Valve protect us from malware? I was searching for "steam games malware" on DDG and found out that there were a few incidents regarding this. I understand that Steam probably has a robust mechanism for understanding game behavior but it's kind of a black-box for us.
Is there any independent vulnerability checker for games? How paranoid should one be before downloading games from steam?
PS: I know that as Linux users, most attack vectors don't work for us but it's good to be aware just in case.
Edit: I need to clarify. I know Steam is just a game-launcher, it's not supposed to protect the user after the game is installed. I meant to say how does Valve protect the user from malicious games? Is their mechanism known?
I mean, once you invoke a game once outside a sandbox, all bets are off from that point on. It can modify your environment to do whatever from that point on. Like, it could, oh, modify your
~/.bashrcto invoke some keylogger binary that it drops off somewhere in your home directory. Just closing the game isn't going to be a reliable mechanism for preventing malware in a game from dicking with the system after that point.