I did not answer their call, but instead called the number back.
After several rings, a woman with a very quiet Indian accent said they were 'Archie' from a company called 'IT Security' and wanted my name so they could send a free whitepaper.  I told them to remove me from their list.

Calls from this number repeatedly on my work phone, but no message.  

Called and no message - had 4 calls one after the other but no message.Other numbers calls originated from were:
415-413-2311
415-253-1142
732-504-2207