First off (in the image) this isn't an Avast message as far as I can tell (certainly not Avast for Windows), but a detection on an entry in the avast download/defs, references to avast download and vps9 locations, etc. Also these aren't Avast for Windows locations.
The fact that it is also 'validly signed by Apple' in the image also, I would have to ask is this Avast for Mac installation if so it should be in the
Avast Mac Security sub-forum.