I already said this is not unique to Windows. Such that I don't see the point of the first question. On whether those have been source of attacks, I don't have numbers. I do remember getting hacked through Office back in the day. The whole "open this document" crap college students did to each other. To that end, I fully cede this could just be a false view from my side.

I'd expect most attacks are still of the "what is your password" variety. That along with a giant shared drive that everyone just dumps everything into.

And I don't mean this as an offensive against just Microsoft. They are/were somewhat unique in the success they had with embrace/extend. That said, the blame almost as surely rests on typical "growth at all costs" mental model that is modern business.