Sure, but only if you’d installed the affected AUR packages. Even if they were old packages, probably your SteamOS didn’t install them from the AUR.
Whether or not SteamOS installed them is irrelevant. All the hacker would need is to compromise a machine that had some sort of remote access to other devices (ssh in this case, with some sort of keylogger to decrypt the private key).
Whether or not SteamOS installed them is irrelevant. All the hacker would need is to compromise a machine that had some sort of remote access to other devices (ssh in this case, with some sort of keylogger to decrypt the private key).