SSH BACKDOOR - A portable open-ssh server

Disclaimer

This is a fork of NinjaJc01's project, all credits belong to him. The purpose here is to try to improve and maintain his beautiful project, not to steal his stuff.

Context

Having a reverse-shell on a machine (in a legal situation of course) is good, but a ctrl+c can happen quickly and it's quite annoying.

And when you do manage to get a shell, it's often with a user who doesn't have the rights to generate a private/public key pair in his home directory.

So, while wandering around on Github, I came across this tool, made by a developer from TryHackMe.

After testing it, I found it absolutely beautiful. Besides it is written in go, a language I would like to learn. So this project is the opportunity for me to learn it and to contribute to his project.

How to use

1. Create an hidden directory (optionnal)

2. Download the backdoor binary according the target machine archa and distro, then upload it.

   The binary has only been tested on x86_64 machines. Feel free to build for the other archs :)

3. Generate the id_rsa key pair in the directory you want.

   user@victim ssh-keygen -f ./id_rsa

   Password protected private keys are not supported

4. You are ready to go ! Just launch ./backdoor with the options you like.

   By default, password is password and listening port is 2222. So if you are on a shared machine, you should use a random/strong password. Also, don't forget to delete your traces by deleting the binary.

Optional options

-a, --hash : Password hash to be verified.
-p, --port : Specify port to bind.
-k, --key : Path to private key.
-i, --interface : Interface to listen on.
-p, --fingerprint : SSH Fingerprint, excluding the SSH-2.0- prefix.
-r, --rand-pass : Generate a random password of a given length.

Demo

Linux

Known ssh issue

If you encounter this type of error :

Unable to negotiate with <ip> port <port>: no matching host key type found. Their offer: ssh-rsa

You have to append this to your ssh command : -oHostKeyAlgorithms=+ssh-rsa

List of compatibles arch/distro

Only AMD64 (x86_64) for the moment

• Debian
• Ubuntu
• Centos
• Fedora
• Manjaro
• Alpine
• Archlinux

To do

• : Add a random password generator
• : Add Windows compatibility
• : Build for more platforms