Hey there, Fabmilsty.
You could try reformatting it by using an SD card/flash drive formatting tool, to see if that fixes things up. Most manufacturers offer such tools for their devices.
It's doubtful that this is a virus, but you could scan it with antivirus and antimalware programs, just to be on the safe side and after that try the card with a different device, to see if the same thing happens.
Hope that helps.
Boogieman_WD