Ninja is the freeware zero-configuration program designed for guarding computers against viruses transmitted by USB pendisks.
This ninja awaits quietly in the system tray for the times whenever a USB pendisk is inserted on the computer which will be examined to uncover the commonly malicious or virulent files known as "autorun.inf" and "ctfmon.exe" amongst many others.
To keep things simple, ninja is fully portable, self-contained and requires no installation.
Besides removing known virulent files, this tool will also immunize your pendisk and create a folder called autorun.inf with special protection permissions to protect your pendisk from being infected again when plugged on contaminated computers.
Author website : http://nunobrito.eu/