Used lg g2: atnt d802??

Hey, my friend bought a used lg g2. We've tried to identify if it's original or not by checking it with cpu-z online verification. I've found something interesting. It says that it's atnt version, but it says it's d802. How is this possible? It had cyanogenmod pre-installed..
1st thought was that it's d802 with d800 motherboard. Is it possible? If so, which roms should I install?