Until last year there was a boiler room scam where some person (usually of Indian descent) would call and claim to be from “Microsoft technical support”. They would then try to get you to install a patch that was in fact a virus or worm to ‘fix’ your machine. All I can say is it sure would ‘fix’ your machine.
It stopped when the police in London arrested the organizers.
It’s back, but with a new twist. They now DoS attack a relevant IP address first, then suddenly your machine is fixed.