Windows use a text file call autorun.inf to automatically trigger setup.exe program.
Virus writer use this feature to auto trigger their virus. If your USB pendisk is infected.
The moment you plug in, you will be infected.
Tips to immune your PC against autorun virus without help from antivirus program.
create autorun.inf FOLDER at c:\
c:\autorun.inf
if you have 2 partitions
d:\autorun.inf
if your USB pen drive is at f:
d:\autorun.inf
The virus think that it have already infected your PC because a folder with the same name as autorun.inf exist.
So your PC will be immune.
Another method is to disable the autorun at the windows registry.
You can use the following batch file to clean your PC.
copy and paste to a notepad file and save as killauto.bat
Then click and run.
It will remove the autorun.inf and create folder with same name to prevent it from coming back.
===========DOS batch file ===================
ECHO off
ATTRIB -r -s -h A:\autorun.inf
DEL /Q A:\autorun.inf
MKDIR A:\autorun.inf
ATTRIB +r +s +h A:\autorun.inf
ATTRIB -r -s -h B:\autorun.inf
DEL /Q B:\autorun.inf
MKDIR B:\autorun.inf
ATTRIB +r +s +h B:\autorun.inf
ATTRIB -r -s -h C:\autorun.inf
DEL /Q C:\autorun.inf
MKDIR C:\autorun.inf
ATTRIB +r +s +h C:\autorun.inf
ATTRIB -r -s -h D:\autorun.inf
DEL /Q D:\autorun.inf
MKDIR D:\autorun.inf
ATTRIB +r +s +h D:\autorun.inf
ATTRIB -r -s -h E:\autorun.inf
DEL /Q E:\autorun.inf
MKDIR E:\autorun.inf
ATTRIB +r +s +h E:\autorun.inf
ATTRIB -r -s -h F:\autorun.inf
DEL /Q F:\autorun.inf
MKDIR F:\autorun.inf
ATTRIB +r +s +h F:\autorun.inf
ATTRIB -r -s -h G:\autorun.inf
DEL /Q G:\autorun.inf
MKDIR G:\autorun.inf
ATTRIB +r +s +h G:\autorun.inf
ATTRIB -r -s -h H:\autorun.inf
DEL /Q H:\autorun.inf
MKDIR H:\autorun.inf
ATTRIB +r +s +h H:\autorun.inf
ATTRIB -r -s -h I:\autorun.inf
DEL /Q I:\autorun.inf
MKDIR I:\autorun.inf
ATTRIB +r +s +h I:\autorun.inf
ATTRIB -r -s -h J:\autorun.inf
DEL /Q J:\autorun.inf
MKDIR J:\autorun.inf
ATTRIB +r +s +h J:\autorun.inf
ATTRIB -r -s -h K:\autorun.inf
DEL /Q K:\autorun.inf
MKDIR K:\autorun.inf
ATTRIB +r +s +h K:\autorun.inf
ATTRIB -r -s -h L:\autorun.inf
DEL /Q L:\autorun.inf
MKDIR L:\autorun.inf
ATTRIB +r +s +h L:\autorun.inf
ATTRIB -r -s -h M:\autorun.inf
DEL /Q M:\autorun.inf
MKDIR M:\autorun.inf
ATTRIB +r +s +h M:\autorun.inf
ATTRIB -r -s -h N:\autorun.inf
DEL /Q N:\autorun.inf
MKDIR N:\autorun.inf
ATTRIB +r +s +h N:\autorun.inf
ATTRIB -r -s -h O:\autorun.inf
DEL /Q O:\autorun.inf
MKDIR O:\autorun.inf
ATTRIB +r +s +h O:\autorun.inf
ATTRIB -r -s -h P:\autorun.inf
DEL /Q P:\autorun.inf
MKDIR P:\autorun.inf
ATTRIB +r +s +h P:\autorun.inf
ATTRIB -r -s -h Q:\autorun.inf
DEL /Q Q:\autorun.inf
MKDIR Q:\autorun.inf
ATTRIB +r +s +h Q:\autorun.inf
ATTRIB -r -s -h R:\autorun.inf
DEL /Q R:\autorun.inf
MKDIR R:\autorun.inf
ATTRIB +r +s +h R:\autorun.inf
ATTRIB -r -s -h S:\autorun.inf
DEL /Q S:\autorun.inf
MKDIR S:\autorun.inf
ATTRIB +r +s +h S:\autorun.inf
ATTRIB -r -s -h T:\autorun.inf
DEL /Q T:\autorun.inf
MKDIR T:\autorun.inf
ATTRIB +r +s +h T:\autorun.inf
ATTRIB -r -s -h U:\autorun.inf
DEL /Q U:\autorun.inf
MKDIR U:\autorun.inf
ATTRIB +r +s +h U:\autorun.inf
ATTRIB -r -s -h V:\autorun.inf
DEL /Q V:\autorun.inf
MKDIR V:\autorun.inf
ATTRIB +r +s +h V:\autorun.inf
ATTRIB -r -s -h W:\autorun.inf
DEL /Q W:\autorun.inf
MKDIR W:\autorun.inf
ATTRIB +r +s +h W:\autorun.inf
ATTRIB -r -s -h X:\autorun.inf
DEL /Q X:\autorun.inf
MKDIR X:\autorun.inf
ATTRIB +r +s +h X:\autorun.inf
ATTRIB -r -s -h Y:\autorun.inf
DEL /Q Y:\autorun.inf
MKDIR Y:\autorun.inf
ATTRIB +r +s +h Y:\autorun.inf
ATTRIB -r -s -h Z:\autorun.inf
DEL /Q Z:\autorun.inf
MKDIR Z:\autorun.inf
ATTRIB +r +s +h Z:\autorun.inf