Strange USB corruption

My friend recently found this strange thing going on with his USB he uses for his 3D Printer, and I was wondering on how to fix it? I figure its probably just corruption, but it doesn't look like anything that I've seen online. It has (reportedly) 6,824 files that with names like e1066.4.089, that were made on 1/1/1996 at 5:17 AM They seem to be random dates, and all but at least 600 of the files follow the same naming convention. Those 600 files have disappeared since, but they had names something like X followed by a random string.

Any clue what this might be or how to fix it?