Day 9: Password Attacks
Master the art of password cracking through online brute-force attacks with Hydra, offline hash cracking with John the Ripper and Hashcat, and learn to identify and exploit weak password security.
Learning Objectives
- ✓Understand the difference between online and offline password attacks
- ✓Master dictionary attacks vs brute-force methods
- ✓Use Hydra for online brute-force attacks on SSH and HTTP services
- ✓Crack password hashes with John the Ripper and Hashcat
- ✓Identify different hash types using hash-identifier tool
- ✓Understand NTLM hash capture concepts with Responder
Online vs Offline Password Attacks
Understanding the fundamental approaches to password cracking
Online Attacks
Direct attacks against live services requiring network connectivity
Examples
- • SSH brute-force
- • HTTP login forms
- • FTP authentication
- • RDP services
Tools
- • Hydra
- • Medusa
- • Patator
- • Metasploit modules
Pros
- • Immediate feedback
- • No hash files needed
- • Works against current passwords
Cons
- • Noisy (detectable)
- • Rate limiting
- • Account lockouts
- • Network dependent
Offline Attacks
Attacks against captured hash files without network interaction
Examples
- • /etc/shadow hashes
- • SAM database dumps
- • Zip file passwords
- • Database dumps
Tools
- • John the Ripper
- • Hashcat
- • Ophcrack
- • Rainbow tables
Pros
- • Stealthy (undetectable)
- • No rate limits
- • Can use GPU acceleration
- • Multiple attack modes
Cons
- • Need hash files first
- • Requires storage space
- • Computationally intensive
- • Time-consuming
Dictionary vs Brute-Force Attacks
Choosing the right attack methodology
Dictionary Attacks
- • Use pre-compiled wordlists
- • Faster than brute-force
- • Higher success rate for common passwords
- • Can use rules for variations
- • Examples: rockyou.txt, custom wordlists
Brute-Force Attacks
- • Try all possible combinations
- • Guaranteed to find password (given time)
- • Very time-consuming
- • Best for short passwords
- • Examples: mask attacks, incremental modes
Essential Links & Resources
Official documentation and reference materials
🐉
Hydra Documentation
https://github.com/vanhauser-thc/thc-hydra
🔓
John the Ripper Wiki
https://www.openwall.com/john/
⚡
Hashcat Wiki
https://hashcat.net/wiki/
🗝️
WPScan Documentation
https://wpscan.com/
📋
SecLists Repository
https://github.com/danielmiessler/SecLists
🔍
Hash Identifier Tool
https://github.com/psypanda/hash_identifier