Ninja Pendisk

Ninja is a popular and free program designed to protect computers from viruses transmitted by USB pendisks. 
This ninja waits quietly in the system tray for times whenever a USB flash drive is inserted on the computer, which will be considered to reveal often malicious or virulent files known as "autorun.inf " and " ctfmon.exe " among many others. 
To keep things simple, ninja is fully portable, self-contained and requires no installation.
Besides eliminating known virulent files, this tool will also immunize your flash drive and create a folder named autorun.inf with special protection permissions to protect your flash drives from infection again when you connect on infected computers.