Hydra Bruteforce Guide

TL;DR

This guide shows you how to use Hydra to try and guess passwords for various services. It’s a powerful tool, but remember that using it against systems you don’t have permission to test is illegal.

What is Hydra?

Hydra is a parallelized login cracker. It supports many different protocols (like SSH, FTP, HTTP, etc.) and can try various username/password combinations quickly. It’s often used in penetration testing but can also be misused.

Prerequisites

• Linux: Hydra is best suited for Linux environments (Kali Linux is a popular choice).
• Hydra Installed: You’ll need to have Hydra installed. Use your distribution’s package manager. For example, on Debian/Ubuntu:

  sudo apt update
  sudo apt install hydra

• Target Information: You need the IP address or hostname of the target system and the service you want to attack (e.g., SSH port 22).
• Wordlist: A text file containing a list of potential usernames and passwords. Common wordlists are available online, but creating your own tailored lists is more effective.

Step-by-step Guide

1. Basic SSH Bruteforce: This example attempts to brute-force an SSH login.

   hydra -l  -P   ssh

   • Replace <username> with the target username (or use a wordlist for usernames too).
   • Replace <password_list.txt> with the path to your password list file.
   • Replace <target_ip> with the IP address or hostname of the target system.
2. Specifying a Port: If SSH is running on a non-standard port (e.g., 2222):

   hydra -l  -P   ssh -p 2222

3. Using Multiple Threads: Increase the number of threads for faster cracking (be careful not to overload the target system).

   hydra -l  -P   ssh -t 16

   • The -t option sets the number of threads (e.g., 16).
4. Bruteforcing FTP: Example for brute-forcing an FTP login.

   hydra -l  -P   ftp

5. Bruteforcing HTTP Basic Authentication:

   hydra -l  -P   http-post-form "/login.php:username=^USER^&password=^PASS^":method=POST

   • Replace /login.php with the actual login form URL.
   • Adjust the POST parameters if needed (check the website’s source code).
6. Using a Username Wordlist: If you have separate wordlists for usernames and passwords:

   hydra -L  -P   ssh

   • Replace <username_list.txt> with the path to your username list file.
7. Saving Results: Redirect output to a file for later analysis.

   hydra -l  -P   ssh > results.txt

8. Help and Options: Use the -h option to see all available options.

   hydra -h

Important Considerations

• Legality: Always get permission before testing any system. Unauthorized access is illegal.
• Rate Limiting: Many systems have rate limiting in place to prevent brute-force attacks. Be mindful of this and adjust your thread count accordingly.
• Account Lockout: Repeated failed login attempts can lock accounts.
• Wordlist Quality: The effectiveness of Hydra depends heavily on the quality of your wordlists. Use common passwords, variations, and any known information about the target system.
• cyber security measures like two-factor authentication will prevent this attack from working.