The fraud can get pretty sophisticated. I came across a WD external hard drive that visually looked fine. Only when I plugged it in did I notice the size difference, and upon inspecting the SMART tables saw it was a much older Seagate brand drive with bad sectors. Somehow they had managed to swap the drive without making any marks on the case to indicate it had been disassembled. Either that or there's someone selling empty unassembled shells in new condition.