Although not a scam like this, my parents were tricked into buying an "antivirus" product from a phone call from India. The whole thing was a little bizarre as

Although not a scam like this, my parents were tricked into buying an "antivirus" product from a phone call from India. The whole thing was a little bizarre as it wasn't an outright scam. I never got to see the program in working order but I believe it was an actual attempt at creating a real AV product, although probably bundled with spy/malware. By the time they asked me for help their laptop running Windows Vista was riddled startup errors, most referring to non-existing registry entries. My only guess is that the "company" or whatever it was hit some sort of kill switch, leaving their software in a broken state. It took me a while to clean everything up. In the end I think my parents spent a few hundred dollars on the product and nothing suspicious ever happened with their bank account.