Homework

Objective

Design a set of custom charsets tailored to a specific password policy, then use them to crack test hashes.

Instructions

1. Choose a password policy (real or hypothetical). Example: "8 characters minimum, must contain at least one uppercase letter, one lowercase letter, one digit, and one of the following special characters: !@#$"
2. Create 5 test passwords that comply with this policy. Generate their MD5 hashes.
3. Design masks using custom charsets (-1, -2, etc.) that model the policy constraints. Write at least 3 different masks targeting different structural patterns:
   • Example mask 1: -1 !@#$ ?u?l?l?l?l?d?d?1 (uppercase + 4 lower + 2 digits + special)
   • Example mask 2: -1 !@#$ ?1?u?l?l?l?l?l?d (special + uppercase + 5 lower + digit)
   • Example mask 3: -1 !@#$ ?d?d?u?l?l?l?l?1 (2 digits + uppercase + 4 lower + special)
4. Run each mask against your test hashes. Record which passwords each mask cracks.
5. Write a brief explanation (3-5 sentences) of why multiple masks are needed even with custom charsets.

Deliverable

A text file or document containing: the password policy, your 5 test passwords, the 3+ masks with their commands, results, and your explanation.

Objective

Compare the performance of mask, hybrid, and dictionary attacks on identical hash sets to understand when each mode is most efficient.

Instructions

1. Create a set of 10 test passwords that include a mix of:
   • Pure dictionary words (e.g., "sunshine")
   • Words with appended digits (e.g., "sunshine123")
   • Pattern-based passwords (e.g., "Abcd1234")
   • Words with prepended digits (e.g., "99sunshine")
2. Generate their MD5 hashes into bench_hashes.txt.
3. Run the following attacks and record the time, speed, and number of passwords cracked for each:

   # Dictionary attack
   hashcat -m 0 -a 0 bench_hashes.txt rockyou.txt
   
   # Hybrid append
   hashcat -m 0 -a 6 bench_hashes.txt rockyou.txt ?d?d?d
   
   # Hybrid prepend
   hashcat -m 0 -a 7 bench_hashes.txt ?d?d rockyou.txt
   
   # Mask attack (8-char mixed)
   hashcat -m 0 -a 3 bench_hashes.txt ?u?l?l?l?d?d?d?d

4. Create a results table:

   Attack Mode	Passwords Cracked	Time	Speed (H/s)
   Dictionary (-a 0)	?/10	?	?
   Hybrid append (-a 6)	?/10	?	?
   Hybrid prepend (-a 7)	?/10	?	?
   Mask (-a 3)	?/10	?	?

5. Write a brief analysis (5-8 sentences): Which attack mode cracked the most passwords? Which was fastest? Were there passwords that only one mode could crack? What does this tell you about real-world cracking strategy?

Objective

Write a shell script that chains multiple attack modes in order of efficiency, stopping when all hashes are cracked or all attacks are exhausted.

Instructions

1. Create a Bash script called crack_chain.sh that accepts a hash file as an argument.
2. The script should run the following attacks in sequence:
   1. Stage 1: Dictionary attack with rockyou.txt
   2. Stage 2: Hybrid append — wordlist + ?d?d
   3. Stage 3: Hybrid append — wordlist + ?d?d?d
   4. Stage 4: Hybrid prepend — ?d?d + wordlist
   5. Stage 5: Mask for 4-digit PINs: ?d?d?d?d
   6. Stage 6: Mask for 6-digit PINs: ?d?d?d?d?d?d
   7. Stage 7: Mask for name+digits: ?u?l?l?l?l?d?d
3. Between each stage, print a status message showing which stage just completed and how many hashes have been cracked so far.
4. Test the script against a set of 10+ test hashes covering diverse password patterns.

Starter Template

#!/bin/bash
# crack_chain.sh - Multi-stage hashcat cracking script

HASHFILE="$1"
WORDLIST="rockyou.txt"
HASHTYPE=0  # MD5

if [ -z "$HASHFILE" ]; then
    echo "Usage: $0 <hashfile>"
    exit 1
fi

echo "=== Stage 1: Dictionary Attack ==="
hashcat -m $HASHTYPE -a 0 "$HASHFILE" "$WORDLIST"
echo "Stage 1 complete."

echo "=== Stage 2: Hybrid Append ?d?d ==="
hashcat -m $HASHTYPE -a 6 "$HASHFILE" "$WORDLIST" ?d?d
echo "Stage 2 complete."

echo "=== Stage 3: Hybrid Append ?d?d?d ==="
hashcat -m $HASHTYPE -a 6 "$HASHFILE" "$WORDLIST" ?d?d?d
echo "Stage 3 complete."

# Continue with remaining stages...
echo "=== Stage 4: Hybrid Prepend ?d?d ==="
hashcat -m $HASHTYPE -a 7 "$HASHFILE" ?d?d "$WORDLIST"
echo "Stage 4 complete."

echo "=== Stage 5: PIN 4-digit ==="
hashcat -m $HASHTYPE -a 3 "$HASHFILE" ?d?d?d?d
echo "Stage 5 complete."

echo "=== Stage 6: PIN 6-digit ==="
hashcat -m $HASHTYPE -a 3 "$HASHFILE" ?d?d?d?d?d?d
echo "Stage 6 complete."

echo "=== Stage 7: Name+Digits ==="
hashcat -m $HASHTYPE -a 3 "$HASHFILE" ?u?l?l?l?l?d?d
echo "Stage 7 complete."

echo "=== All stages finished ==="
hashcat -m $HASHTYPE --show "$HASHFILE"