Comments on: Understanding Bash fork() bomb ~ :(){ :|:& };:

By: StarDust

StarDust — Fri, 06 Jan 2012 11:52:04 +0000

I did the %0|%0 command in Windows XP. Type into Notepad and saved as FORKBOMB.BAT then double-clicked. Fortunately, I already had task manager running, so I right-clicked explorer and hit “end process tree” which left me with a blank desktop. I then used Alt+Ctrl+Del to reopen Task Manager and from there, typed explorer.exe in the RUN dialog to get Windows back up without rebooting.

If you add an additional command, for example:

PING [insert url of hated website]

you can spam out DOS attacks as well while you watch your computer crash. Seriously people, don’t do that…

By: Tryme

Tryme — Thu, 01 Dec 2011 15:52:23 +0000

:(){ : | : & }; :

:() is a function name with the open and close parenthesis representing no parameters. The body of this function is within the braces {}.
: | : is a recursive call since : is the name of the function. The function gets called twice and is piping input from one call to the other.
& backgrounds the previous function call so that it will not die.
; finishes the function declaration.
: Calls the function just defined.

By: modchan

modchan — Fri, 07 Oct 2011 10:47:58 +0000

Tried on Mac OS X 10.7.1 from root, bomb was killed in 0.003 s.

By: Ellisgeek

Ellisgeek — Fri, 04 Mar 2011 01:22:34 +0000

try this on for (lack) of size:

#/bin/bash
$0&
$0

Very tiny fork bomb :D

By: Änönymöüs

Änönymöüs — Tue, 11 Jan 2011 16:26:56 +0000

WARNING! These examples may crash your computer if executed.

may?
They WILL crash your comp.
Win7 – batch WILL kill (also input lag)

By: newklear

newklear — Wed, 17 Nov 2010 20:25:30 +0000

PCLinuxOS is immune

By: Victor Chaves

Victor Chaves — Thu, 12 Aug 2010 19:31:21 +0000

Debian 5 is immune to this fork bomb.

By: PyrexKidd

PyrexKidd — Thu, 17 Jun 2010 18:15:56 +0000

On my Ubuntu 10.04 LTS the fork bomb launched about 2500 processes and then my kernel killed it. Total time ~< 5 min.

By: Marc

Marc — Fri, 20 Nov 2009 18:33:58 +0000

How would i send a forkbomb/ebomb to an ip without requiring passwords like the ones controled by keys when u stimotaunisusley press keys it opens up stuff on the targets ip.

By: Edward

Edward — Sat, 17 Oct 2009 13:20:23 +0000

This did 100% of nothing on my AuroraUX^[1] machine.
Load went up for about min to min and a half, then the kernel killed the process for me.
Silly Linux..
[1] – http://www.auroraux.org/

By: Peter

Peter — Mon, 28 Sep 2009 15:55:06 +0000

That would make a VERY geeky tattoo.

:(){ :|:& };:

By: stealth

stealth — Sat, 29 Aug 2009 21:00:41 +0000

Use ulimit -u 30 (where 30 it is a max number of process ) to protect yourself from this attack(or config your limits.conf)

By: sharfah

sharfah — Sat, 22 Nov 2008 14:42:26 +0000

A fork bomb process which can no longer fork exits. The following short Z Shell code will typically get rid of the above fork bomb in about a minute:

while (sleep 100 &!) do; done

It keeps trying and will eventually start a new do-nothing process; Each new do-nothing process reduces the number of rampant “fork bomb” processes by one, until eventually all of them are eradicated, at which point the do-nothing processes can exit.

By: Joe

Joe — Thu, 13 Nov 2008 23:04:38 +0000

This works faster on all windows:

:bomb
start %0
%0|%0
goto bomb

By: bradley

bradley — Mon, 31 Mar 2008 18:06:37 +0000

This works very quickly on all windows:

:bomb
%0 | %0
goto bomb

By: ATOzTOA

ATOzTOA — Wed, 30 Jan 2008 04:15:49 +0000

Sleek code :)

I tried on FC4. Took only 1 minute as root.

In WinXP, I waited till 7 minutes. Displayed some errors and all, but was responding. Tried MS Word, Task Manager, nothing could be executed. The machine was useless untill reset.

By: bort

bort — Wed, 05 Dec 2007 16:21:19 +0000

perl inline…

perl -e “fork while fork” &

By: Bash

Bash — Wed, 28 Nov 2007 14:27:25 +0000

I tried this on a virtual instance of SLAX, and it totally killed it.

By: vivek

vivek — Wed, 28 Nov 2007 12:56:12 +0000

kunal,

Read http://www.cyberciti.biz/tips/linux-limiting-user-process.html

By: kunal

kunal — Wed, 28 Nov 2007 11:52:48 +0000

Hi,

i run it on my testing server and it start consuming my server process.
so one thing is clear from this form bomb that it starting issuing new processes rather than threads.

how we prevent our sites from such fork attacks

Thanks in advance