They called a cell phone that is seldom used and I don't give the number out.  When my son answered there was nobody there.  Did a quick online search, but it appears this number is not widely used by scammer (yet),

Call, no message. No info, most likely spam

called, I don't answer if it is not in my contact list, didn't leave a message

Same as the other folks.  Call from unrecognized number with no message left.

Called and when I answered they hung up!!  Why call if you just going to hang up???