I rely on the free version of Malwarebytes to keep rubbish such as that out, so it might be worth a try to clean your drive up. The version I have runs silently in the background and has done so for many years without a problem. My main AV is AVG Free that runs alongside W-Defender.
It turned out to be the notifications, now turned off all but Microsoft, and the windows show no more, seems it was an advert for McAfee and Norton which has done the reverse, would not touch them now with a barge pole.