Re: Strange Attack On A Webserver I Work On

TJ Easter <[email protected]>
Newsgroups gmane.comp.security.linux
Message-ID <[email protected]>
On Tue, 26 Oct 2004 20:30:37 -0400, Matthew J. Sahagian <[email protected]> wrote:
> Hello, I'm a long time reader of this list and have never really had the need to post here.  However, recently a webserver that I do minimal administrative work for was attacked.  We're still unsure exactly what had been done.  Most of the logs have been either cleaned or wiped completely (either by log rotate or by the attacker).  I was gone for the weekend so I sorta came back to this.  I don't really have questions about the attack per se, we're doing pretty well at the recovery process....  one question I do have however is this.
> 
> The attacker (either manually or using a program) replaced all index.html/htm and index.php files they had permission to replace with a UDP flooder.  I extracted some of the information from the flooder using the strings program and heres what I get:
> 
> !HELP! beta version.
> !HELP!
> !HELP! #brazil@efnet - eleet team
> !HELP! + code by bonny ::: [email protected]
> 
> !CREDITS! * creditos aos amigos e a quem me ajudou.
> !CREDITS!
> !CREDITS! * none        ([email protected]) ::: Brazil
> !CREDITS!   packet spoof
> !CREDITS! * cyclone     ([email protected]) ::: Brazil
> !CREDITS!   parceiro das hackadas, aprende rapido
> !CREDITS! * mariana     ([email protected]) ::: Brazil
> !CREDITS!   minha leet girl, exclusiva :)
> !CREDITS! * alcaloide   ([email protected]) ::: Brazil
> !CREDITS!   super lamer, versao 3 pra pacotar ele
> 
> * Opcao invalida! * %s para maiores informacoes.
> 
> !AJUDA!: %s -help
> 
> CREDITS: %s -credits
> 
> !USAGE!: %s (host/ip) (size) (loops)
> 
> (host/ip) == host do babaca a ser fudido.
> (size)    == bytes a serem enviados.
> (loops)   == tempo da fudecao/s.
> 
> CTRL-C - ACAO CANCELADA!
> 
> FUDEDOR (v3.0) by bonny - PRIVATE!@#!
> host desconhecido: %s
> Maximo de bytes permitodos: 65535.
> 
> A maquina nao tem memoria suficiente.
> 
> FUDENDO A VERA %s COM %s bytes...
> 
> pronto maneh, o babaca foi fudido! :)
> 
> My question to anyone out there who can answer it is this, do you know of any kind of automated attack that replaces index files for websites with such a flooder?  It doesn't seem like this hack was extremely well thought out, or done by anything more than a script kiddy... if it was, why would they replace these files with this binary program?  Why not replace it with a new index.html file saying we got hacked?
> 

Matthew,
   I see two possible scenarios here.

(a)  Zombie network.  This is unlikely due to the text/html and PHP
handlers either not executing code (html) or not being able to
correctly parse (php) the code.

(b)  An errant search/replace find(1) or similar.  Its well within
reason to believe that the kiddie who rooted your box had a UDP
flooder AND a replacement HTML file, and accidently
keyed-in/tab-completed the wrong filename when doing the replace. I've
seen some horrid keying mistakes on compromised equipment.

My guess lies with the latter.  She probably realized the mistake,
said screw it, cleaned the logs with an automated cleaner and cut her
losses.

Any hints in the .bash_history file?  You'd be surprised how many
kiddies forget to clean that file.

Regards,
TJ Easter

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