cheatsheet.md

pycat

Send input standard to a program

pycat TCP-LISTEN -p 1337 Exec -c "ssh user@server"

Send command to an SSH Server

pycat - SSH -d ip -U user -P password

Reading Unix socket

pycat UNIX-LISTEN -b /tmp/test_unix UNIX-CONNECT -d /tmp/ssh-QknJmQenOy19/agent.27601  Logger	

Basic MiTM in a SSH communication

pycat SSH_LISTEN -p 2222 -d ip -U user -P password Logger -H

• Only basic MiTM can be done using this mechanism, for example Agent forwarding won't work. You have to use SSHProxy instead

Socks

SocksClient

• It has to be used when you want to connect to a SOCKS server. Therefore you need to specify, the SOCKS server, and the final destination

pycat TCP-LISTEN -p 64240 SocksClient -d socks_ip -p socks-port -D final_ip -P final_port

SocksServer

• It is like a SOCKS server, this endpoint is supposed to receive SOCKS protocol, so dynamically it will connect to the server specified in the SOCKS protocol

pycat TCP-LISTEN -p 64240 SocksServer

Etherpuppet

• It is possible to get a kind of poor etherpuppet. The goal is to duplicate an ethernet card existing on a machin on another one. For serious purposes, I encourage you to prefer etherpuppet.

On the server where the real card exists :

pycat UDP-LISTEN -p 64240 Interface -i eth0 --bpf ip_client:64240

The BPF filter is important to avoid sending the UDP communication as well inside itself, leading to an infinite loop. The BPF filter resulting will be not ((dst host ip_client and src port 64240) or (src host ip_client and dst port 64240)).

Every packet read on eth0 will be sent in UDP, and every packet read on UDP will be sent to eth0.

On the client where you want to see the same card:

pycat TAP -i pytap0 UDP -d server_ip -p 64240

This command will create a pytap0 interface on the client. As previously, every packet read from UDP will be sent to pytap0 and every packet read on pytap0 will be sent with UDP. This allows to sniff on pytap0 as we were directly on the server. At the same time, it is possible to send traffic to this network interface and it will be sent on the first system.

You have to configure this interface pytap0 is you want to use it for other purposes than sniffing. Many problems can occur:

• If you want to have the exact same IP adress, the UDP commication will probably be cut off, because your system will try to go through this virtual interace to reach the server and not anymore through the classical routing. It will happen if the interface you want to dupicate is the same at the one that receive the UDP communication. You can solve this problem by using iproute2 advanced routing (for example by using a different routing table for this UDP port) or by using a different Linux network namespace
• If you want to get a different MAC address, be sure to set eth0 in promiscous mode (by using the --promisc option). Otherwise, you won't see any traffic destinated to your MAC, because eth0 won't see it. Be sure to use a different IP address, because some nasty things could happen (multiple MAC for the same IP).
• If you want to use the same MAC address and the same IP Adress, be sure to block traffic the outgoing traffic on the server, otherwise you will open communication, than the server itself will cut, because it never opened it.

TCP Tunnel

Be careful, if you use a SOCK_STREAM oriented protocol, such as TCP, you may have some troubles, because network interfaces are datgram oriented. It means that some datagrams can be splitted, or merged before being sent to the interface. You should use the LengthProto using --proto option for such endpoints. Every datagram will be prefixed by its length and this length will be removed by the orther endpoing ensuring that datagram are not splitted/merged. You can find more information about protocols here.

pycat TCP-LISTEN --proto "LengthProto()" -p 64240 Interface -i eth0 --bpf ip_client:64240
pycat TAP -i pytap0 TCP --proto "LengthProto()" -d server_ip -p 64240

pyproxy

TCP Proxy use cases

• Forward data from port localhost port 1337 to ip port 1338 and display data

pyproxy TCPProxy -p 1337 --server-ip ip --server-port 1338 Logger

UDP Proxy use cases

• Forward data from port localhost port 1337 to ip port 1338 using the same source port (--mirror) as the client connecting to port 1337

pyproxy UDProxy -p 1337 --server-ip ip --server-port 1338 --mirror

TLS Proxy use cases

• Decrypt SSL/TLS communication (of course, certificate needs to be allowed on the client)

pyproxy TLSProxy -p 1337 --server-port 1338 -c cert.pem -k key.pem Logger -H

• Perform 10% of bits corruption in the payload embeded in the SSL/TLS communication

pyproxy TLSProxy -p 1337 --server-port 1338 -c cert.pem -k key.pem Corrupt --both -n 10

SSH Proxy use cases

• MiTM SSH communication

pyproxy SSHProxy -p 2222 --server-ip ip --server-port 22 -U user Logger -H

• TODO: command sent in an exec_command channel won't be seen inside the module Logger...

pytun

Create a TCP tunnel to embeds IP traffic between IP_a and IP_b

On host IP_a:

pytun -a 192.168.64.1 TCP -d IP_b -p 8443

It will create a tun0 interface with IP 102.168.64.1. Everything sends to this IP will be tunnelled inside the TCP tunnel established on port 8443 between IP_a and IP_b.

On Host IP_b:

pytun -s -a 192.168.64.2 TCP-LISTEN -p 8443