On the extreme preset you got wmi tools and winsat.
So, I finally found out what it is. Windows Search. Which is really strange, since it doesn't seem to have anything to do with Avast.
Removing Windows Search but keeping Shell search doesn't work?
As I found with Dragon, it seems that some software needs certain components during install. But once installed, they work okay without the component.
Update: I can disable Windows Search in the "Features" section, I can disable the Windows Search service and Avast would still run fine. Only when I remove it would Avast stop working.