It was running in my XP and win10 systems and whilst it didn't use any CPU activity, AvastSvc.exe was in my case (winXP system) using a lot of CPU. This only seemed to appear after the 18.6 version and someone posted that they believe it was associated to the behaviour shield. If this is the case then the behaviour shield would be under the control of the main avast service, AvastSvc.exe and that was what
I'm not having this issue on my win10 system, unsecapp.exe is running but I'm not experiencing cpu spikes by AvastSvc.exe.
This is why I went back to avast version 18.5.2342, no unsecapp.exe running and so fare no cpu spikes by AvastSvc.exe.