I installed Stalkersoup a week or so ago, not on the C: drive, and have played a little.....just past the first time through the labrynith.
I shut my computer down at least once a day, but most days since initial install and update, whether or not I have started the launcher or played the game, the updater starts on its own.
When I look for anything in task manager, I don't see anything that appears to be related, at least on the surface and all this makes me think I may be infected with some sort of malware. My brother has been playing for years and this does not happen on his Win 10 machine.
I am on the Win 10 insiders beta-slow ring if it helps.