Hydra: Bypassing Timeout & 4 Billion Limit

TL;DR

This guide shows you how to use Hydra to perform brute-force attacks without being stopped by timeouts or the default 4 billion password limit. We’ll cover configuring Hydra for longer runs and larger wordlists.

Solution Guide

1. Understand the Limits: By default, Hydra stops after trying approximately 4 billion passwords to prevent excessive resource usage. It also has timeout settings that can cut off attacks if a service doesn’t respond quickly enough.
2. Disable the Password Limit: Use the -f option with a very large number (effectively disabling the limit). For example:

   hydra -l  -P /path/to/wordlist.txt  -f 9999999999

3. Increase Timeout Values: The -t option controls the timeout in seconds. Increase this value if your target service is slow to respond.

   hydra -l  -P /path/to/wordlist.txt  -t 60

   This sets the timeout to 60 seconds per attempt. Adjust as needed.

4. Ignore Connection Errors: Use the -vV option for verbose output and error reporting. This helps identify connection issues.

   hydra -l  -P /path/to/wordlist.txt  -t 60 -vV

5. Use Multiple Threads: Increase the number of threads with the -w option to speed up the attack, but be mindful of resource consumption and potential detection.

   hydra -l  -P /path/to/wordlist.txt  -t 60 -vV -w 16

   This uses 16 threads.

6. Configure for Specific Protocols: Hydra supports many protocols. Ensure you’re using the correct protocol flag (e.g., -s ssh, -s ftp). Incorrect protocol selection will lead to failed attempts.

   hydra -l  -P /path/to/wordlist.txt  -t 60 -vV -w 16 -s ssh

7. Dealing with Slow Connections: If you’re experiencing frequent timeouts even with increased timeout values, consider the following:
   • Check your network connection.
   • The target service might be overloaded or rate-limiting requests.
   • Reduce the number of threads to avoid overwhelming the server.
8. Wordlist Considerations: A larger, more comprehensive wordlist will increase your chances of success but also significantly lengthen the attack time.
9. Example for SSH Brute Force (Ignoring Limits):

   hydra -l testuser -P /usr/share/wordlists/rockyou.txt 192.168.1.10 -t 120 -vV -w 32 -s ssh -f 9999999999

10. Important Disclaimer: Brute-force attacks are illegal without explicit permission from the target system owner. This guide is for educational purposes only and should not be used for malicious activities. Always obtain proper authorization before conducting any security testing.