Who called from 4243311804

I've been receiving calls from this number, 424-331-1804, a few times a week for a few weeks now. I answered the first 3-4 times, "Hello?" but no one ever responded, so I now let this number go to the machine. They leave no msg, just hang up after a few seconds.  They called this morning (Sunday) at 7:30, and they just called the 2nd time today at 8:35pm.  It's tiresome and irritating.

Got a call this am at 820 - a mans voice saying hello are you there - I hing up and no call back.

Machine generated call. Just dead air when you pick up. Scammers. They blow dead bears.

It's SUM DUM FUK calling. (From North Korea).

Just received same call. Must be a government caller checking for [***].