Pakistani scammer trying to get you to log in on a computer to computer site where he will lock you out of your computer and then ransom the data back to you.
I have been plagues by calls several times today from 1-000-000-0000. I finally blocked the number through my phone. After two blocked attempted calls, I got another call, supposedly from South Carolina from 864-555-0174, which I have now also blocked. I suspect it is the same creeps. Whoever it is seems to be very determined and persistent. I have no unpaid debts, so it's got to be a scammer.