Basic Password Cracking with Hashcat

Master the fundamental techniques for cracking passwords using Hashcat.

1. Dictionary Attacks

Dictionary attacks use a list of words (wordlist) to attempt cracking a password. This is often the first step in password cracking.

Basic Dictionary Attack

Use a wordlist to crack an MD5 hash

hashcat -m 0 -a 0 hash.txt wordlist.txt

This command uses the wordlist.txt file to attempt cracking the MD5 hash(es) in hash.txt. The -m 0 specifies MD5 mode, and -a 0 indicates a straight attack using the provided wordlist.

2. Rule-Based Attacks

Rule-based attacks apply modifications to words in the wordlist, increasing the chances of cracking passwords that are variations of dictionary words.

Rule-Based Attack

Apply rules to a wordlist attack

hashcat -m 0 -a 0 hash.txt wordlist.txt -r rules/best64.rule

This command applies the best64.rule to each word in the wordlist, generating multiple password candidates per word. Rules can significantly increase the effectiveness of your attacks.

3. Basic Mask Attacks

Mask attacks use patterns to generate password candidates. They're useful when you know something about the password structure.

Basic Mask Attack

Crack passwords with a specific pattern

hashcat -m 0 -a 3 hash.txt ?d?d?d?d?d?d?d?d

This command attempts to crack passwords that are exactly 8 digits long. The ?d represents any digit (0-9).

4. Combination Attacks

Combination attacks use two wordlists to create password candidates by combining words from both lists.

Combination Attack

Combine words from two wordlists

hashcat -m 0 -a 1 hash.txt wordlist1.txt wordlist2.txt

This command combines each word from wordlist1.txt with each word from wordlist2.txt to create password candidates.

5. Hybrid Attacks

Hybrid attacks combine wordlists with masks, allowing you to add patterns before or after dictionary words.

Hybrid Wordlist + Mask Attack

Append digits to dictionary words

hashcat -m 0 -a 6 hash.txt wordlist.txt ?d?d?d?d

This command appends four digits to each word in the wordlist. The -a 6 specifies a hybrid wordlist + mask attack.

Tips for Success

  • Start with smaller wordlists and gradually increase size
  • Use rules to expand your password candidates
  • Customize masks based on known password policies
  • Combine different attack methods for better results
  • Monitor your hardware temperatures during long cracking sessions

Next Steps

Ethical Considerations

Always use Hashcat responsibly and ethically. Only attempt to crack passwords on systems you own or have explicit permission to test. Unauthorized access to systems or data is illegal and unethical. These techniques should be used for educational purposes, security testing, and password recovery on your own systems.