I am not expert, but I dont think these USBC + strange characters are viruses. I had the same because of a glitch of the USB card reader.
In my case it happened when I was transfering 500 pictures from the card to the computer using the USB Card reader, it did not connect well and in a blip all those 500 pictures turned into a series of files and folders with a mix of symbols that could not open and my pictures were gone.
I managed to recover all using the checkdisk command + Photorec. I think if I had click on show hidden folders I may had been able to get my files after the checkdisk because the FOUND 0000 folder was invisible
Mind that many users do not advise to use the checkdisk command, and it makes sense.