Date: Sun, 14 Mar 1999 14:34:29 -0700 (MST)
From: mea culpa <jericho@dimensional.com>
To: InfoSec News <isn@repsec.com>
Subject: [ISN] Anatomy of a fairly easy attack


>From: Subash Raman <subash@hotmail.com>

An anatomy of a fairly easy attack

Once upon a time, an auditor was asked to prove that an organizations
machines are not insecure. Their lamentable naivete notwithstanding, the
auditor got them to sign the necessary legalese and then turned his
attention to the task at hand. Some background for those who like their
detail It was an NT environment with SQL Server 6.5 So our hero starts his
venture by first running a tool called chronicle which tells him what
service packs are running on which servers. That eliminates a lot of
unnecessary probing for vulnerabilities does it not. When he realised that
they are only running SP-3 and no other patches have been applied and
furthermore on realising that they are using SMS (client server network
management s/w)  he uses sechole (easily obtainable from the net) and gets
in as a domain admin from a lowly regular account. 

Their PDC turned out to be fairly easy since their registries were
unprotected He next ran a find and lo and behold found two default
accounts with passwords scripted in the registry. Next using these
accounts he attached to their shares (hidden of course only redbutton had
no trouble finding them)  and then proceeded to download the SAM's and
what's of more interest the drwtsn32.log file. 

Sadly the log file didn't contain much interesting data of the variety he
was after but he did glean from them an internal webserver that was
accessing them. So back to info gathering he scanned the entire network
and picked up the webservers. A few quick perlscripts (and a very nifty
tool called the grinder which can recursively go through the urls
automatically) and he nailed the server he was after. Using the datastream
technique he managed to get hold of the source code for the asp scripts
esp. global.asa and lo and behold the connection objection had the userid
and password for their sqlserver right there. In a matter of minutes he
was inside the server again with isql getting the creditcard information
he had been challenged to find. 

redbutton, grinder, couple of perlscripts to parse through the data,
whatsup gold to do network maps (and portscans) and he was inside
literally the corporate data vault in a matter of a couple of hours. 

If he was a real hacker and he didn't have access to a webserver using ASP
code, he could have still done it by <you guessed it> running a
particularly nasty DOS attack to bring the SQL Server crashing down and
then going through the log. Dumpster diving is not considered very
glamourous but you will agree that most insider hacking is based on
examining core dumps by knowledgeable debuggers. In the case of the NT
logs you don't even need to know how to core analysis, all you have to
know is english and have enough patience to keep going through them till
you find the info you are looking for. 

Since he was inside SQL Server with sa privileges he ran xp_shellcmd and
added himself as a user and then proceeded to add the id to the global
domain admins group as well just to make a long story short. 

Why did I do this anatomy of a typical attack ? And what are the dangers
of teaching people such methods ? 

Lots generally, but to tell you the truth if somebody had spend some time
cleaning up the registries, applying the key post sp-3/sp-4 hotfixes and
then ensured strict compliance with policies such as no clear text
scripting when it came to coding and removal of stored procedures such as
xp_cmdshell with more specific stored procedures then it would have been
far more difficult to have done what I did. and the tools i mentioned can
be got off the internet very, very easily. So you are definitely not
underestimating the dangers when you warn people.  I just felt that it is
also necessary to further prove the point by writing this article of how
somebody would actually go about doing it. 

Hope this enlightens more than it obfuscates. Have to admit that this note
coming at the end of a day spent trying to establish the need for both
policy, awareness and a protection strategy that pays equal attention to
prevention, detection, reaction and alleviation is probably why I decided
to break my usual silence on this matter and come out in the open about
this. Plus I am beginning to feel that we are fighting a losing battle
trying to raise awareness and are being drowned by the focus on the media
driven threats as opposed to the real ones. Oh well, maybe I'll go back to
doing budget management. At least forecasting models are a lot less dicier
to deal with than security issues. 

regds,
-sr

P.S. and don't ask me for the name of the poor auditor. he's far too busy
to have the time to answer your questions and he's far too modest to want
to relinquish his identity and come out of the closet anyway <grin>


-o-
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