I have not used Recuva, but I also have this file, along with mdb7.db and mdb7.log . Backup files of some kind? I use this card now only for GoPro, BUT there is a WinRAR archive on the card with lots of pictures saved from my old phone ( I was unable to connect my phone via USB directly to my computer, so at some point I used this microSD card to transfer my phone's pictures and videos). I'm guessing this is why I have these files we mentioned above, from doing some sort of "backup"-type process with my phone in the past. Other than that I used the card for a RaspberryPi device, and uploaded video game emulators, but that was longer ago, and I think the card was reformatted between then and the later uses (phone and then GoPro). I don't know if this helps shed any light on your situation, but good luck!
