I was just wondering what would happen if I downloaded a game that was infected by a computer virus and ran it in Linux using Proton.
Has this happened to anyone? How would the virus behave? What files, connections or devices would it have access to? Could it be as damaging as running in in Windows?
Proton isn’t designed to be a security layer and afaik doesn’t go out of its way to sandbox applications. I’d expect a lot of viruses will fail to do anything, but there’ll also be some able to do things like steal your browser or discord passwords.
There’s no reason to risk it; don’t run anything in Proton that you don’t feel safe running on Windows.
Proton is only sandboxed if you use it with a flatpak Software. Ether steam, bottles or Rufus, all of them available as flatpak.
You may need flatseal to give it access to specific stuff outside the sandbox, like mounted isos, for example.