Years ago my in laws bought some AA batteries in a little podunk town that you can’t get to from here. They didn’t notice the batteries said ‘DURASELL’ not ‘DURACELL’. The batteries were the same diameter as a AAA battery.
Duracell was very interested, and wanted to know where they were sold. My in laws just knew it was somewhere they stopped for lunch in New Mexico. I sent the batteries and my in-laws got a bunch of coupons for free batteries.
Here is a freeware program called ValiDrive. It is from Steve Gibson of the Security Now podcast so I trust it. “Check any USB mass storage drive for fraudulent deliberately missing storage”