I'm the first one, so this may have been a "fat-fingered" dial.
I got a call from an unrecognized number.  No message was left.  As usual, I did not answer, and I looked up the number here.  (800Notes is my go-to.)  I may be adding this number to my "Telemarketer" contact, which has a silent ringtone and is blocked.  (And then, I won't be bothered by this number again.)  for me, an Unrecognized Number + No Message = Scamarketer.

"Honest Business men don't conceal their place of business." - Arthur Conan Doyle, The Adventure of the Three Gables