If you do get that phone call from “John at Technical Services” (who you are certain is a scammer) telling you they have detected a virus on your computer and need to work with you to get rid of it, don’t hang up. Just calmly say “The virus told me you would call. It said someone would want me to get rid of it. But the virus has been nicer to me than most people have. It says I should get rid of anyone who calls wanting to get rid of it. Can you give me your address?”