This one originates in Assam, India. Apparently they call through a US phone so it looks like a call from the US on your Caller ID. It's obviously a phishing scam.
The best thing to do is not answer your phone AT ALL!
Sounds drastic, but legitimate callers will leave a message. Family and friends know you don't answer your phone unless you know the caller. Let the call go to voice mail if you have it, then Google the number or use this 800notes site. A robocaller can distinguish between an electronic answer and a human answer. If you don't answer it will just disconnect and go to the next number. The purpose of this is to "harvest" live numbers that can be compiled into lists that can be sold to telemarketers.