We just got ours today. What weird numbers! We thought it was a scam.
Several years ago when we lived in TX, I worked for a medical billing company and one of my duties was finding people that had skipped out and never paid their medical bills. We had a computer program that allowed us to track anyone and it mainly used their SS#. Our employer advised us to check our own SS# and make sure no one was using it. When I ran my husbands I found it had been used by 3 other people.....2 in CA and 1 in FL. We assumed it was illegals. The interesting part about it was, we went to the SS office and showed them the information and they said there wasn't anything they could do about it.