I don't remember if this is normal but I notice sometimes System (PID 4), just regular system, no extensions and no System Idle Process, when opening programs or watching youtube, I notice it will sometimes use from 3%-16% of my CPU, I don't remember it always doing this, trying to do research online lead to lots of people talking about Vundoo or failing hardware but they said it was using 100% when that happened.
I couldn't find anything with an up to date Avast and Malwarebytes, so I figured I'd come and ask on here.