Called 5 times within 3 minutes at 3am in the morning. Although it won't do any good because it is a spoofed number I still blocked it.

The first time there was no one on the line after I answered and identified myself and my company and said "Hello" three times.  I hung up.  The second time 30 seconds later "Anna" from "Technologic Research Assets" called and in very bad English (she is obviously from India) said she had papers for me and would e-mail them to me on "x" topic.  Unclear with her accent what "x" was.  Told her no, I didn't want any e-mail and take me off the list.

Got the same thing today only it was "Stewart."

Same kind of call. Knew my name and title because I am a federal employee. Then a long, indecipherable sentence where the words "cloud" and "email" were the only words I could make out. OK? He asked. I said "no", because I did not understand a thing you said. He then started with, "I was referred to you by Danny". I tried to tell him 1) I do not know a DANNY, professionally or personally. 2) I am not in a buying position within the government (little white lie), and I STILL cannot make out anything you are saying. He then got angry and said "no no no, LISTEN.." That is when I politely said "No, YOU listen - you are wasting my time trying to send or sell me something. I have no time for this right now. Good day".  2 minutes out of my day I cannot get back.  :)

This week started receiving calls multiple times daily from this set of numbers:
800-347-9623
606-257-4144
620-206-1256
650-399-7008
They didn't leave any messages.  However my machine started recording before they hung up on two of the calls (and from different phone numbers).   I could hear many conversations in the background, like a call center.  The two recordings sounded the same so I suspect all 4 numbers are being spoofed by the same caller.