Somebody used my USB drive and upon returning it to me, I found a autorun.inf that is undeletable. I tried changing it's file attribute which is only H (not even set as a system file) but it keeps on saying Access Denied. The USB is set on FAT32, upon asking my friend, he told me that he uses Panda USB Vaccine http://research.pandasecurity.com/Panda-USB-and-AutoRun-Vaccine/ How do they do this? Im trying to use some Disk Sector editor but have no idea which hex file they change to make this kind of file and make it deletable again. Formatting the drive removes it, but I'm curious as to how to be able to set those kind of file attribute.