Undeletable new folders?

[skyconnorrocks]

The other day, I had noticed on my SanDisk 16 Gigabyte Flash Drive that in an existing folder, there was a new folder, and 3 new files that I hadn't put in, the folder name being "want an. es" and the files being "shows t.hey" "hat must. be" and "rs a mon.th," with that comma being part of the name. File sizes are well over a Mega Byte large, don't seem to exist, don't take memory, and made not only the existing folder undeletable, but all the files I had made previously were replaced by these. Anyone have any ideas?

 

[CountMike]

That sounds like malware.