I received a similar call as Mr Maturana. I think it was a hacker. The guy calling said his name was Matthew and that his company is called Online PC Expert. He insisted he was NOT a hacker, which makes me think he was. He wanted me to log into my computer. I said I was not at my computer. He then wanted to know a good time to call back and I said I'll get back to you and asked for the number. He gave me the number 347-286-1992. He was very pushy and persistent. I am certain this is a scam artist.
I got a call from a guy named Randy Richards (claiming to be from Microsoft) wanting to diagnose my system. He said his phone number was 647-694-0562.
The last time these guys called me I asked for some sort of ID number to prove who they were. They got a little smarter this time and provided me a CLIS ID this time. Apparently this ID is the same across any computer of something.
This is clearly a scam so I took the liberty of keeping him tied up on the phone for about 1 hour. I just played stupid asking a bunch of crazy questions. I could tell he was getting quite frustrated with me.