fix now not working, unauthorized access attack and weird / folder that cant be deleted

Hello,

Recently I was browsing through my computer when my Norton product said I was at risk. I try fixing it but it always shows up fix not complete, I went to my history and it said I was getting attacked by C:/windows/system32/osk.exe every 1 minute, I cant do anything to fix it please help me. P.S. While streaming through my files I found a folder named "/" on my USB I cant delete it and every time I click it just loads the same file "/" continually.  (also I cant upload screen shots because it wont let me)