# Performing Hash Cracking With Hashcat

> Use when hash cracking is an essential skill for penetration testers and security auditors to evaluate password strength. Hashcat is the world's fastest password recovery tool, supporting over 300 hash types w. Use when working with performing hash cracking with hashcat.

- Skill: `oyi77/performing-hash-cracking-with-hashcat` (Agent Skill)
- Install (CLI): `npx skillmds add oyi77/performing-hash-cracking-with-hashcat`
- Raw SKILL.md: https://api.skillmd.com/api/skills/oyi77/performing-hash-cracking-with-hashcat/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Security
- License: Apache-2.0
- Author: oyi77 (https://skillmd.com/u/oyi77)
- Updated: 2026-09-08
- Page: https://skillmd.com/skills/oyi77/performing-hash-cracking-with-hashcat

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# Performing Hash Cracking with Hashcat

## Overview

Hash cracking is an essential skill for penetration testers and security auditors to evaluate password strength. Hashcat is the world's fastest password recovery tool, supporting over 300 hash types with GPU acceleration. This skill covers using hashcat for authorized password auditing, understanding attack modes, creating effective rule sets, and generating hash analysis reports. This is strictly for authorized penetration testing and password policy assessment.


## When to Use
**Trigger phrases:**
- "performing hash cracking with hashcat"
- "Hash cracking is an essential skill for penetration testers and security auditor"


- When conducting security assessments that involve performing hash cracking with hashcat
- When following incident response procedures for related security events
- When performing scheduled security testing or auditing activities
- When validating security controls through hands-on testing

## Prerequisites

- Familiarity with cryptography concepts and tools
- Access to a test or lab environment for safe execution
- Python 3.8+ with required dependencies installed
- Appropriate authorization for any testing activities

## Objectives

- Identify hash types from captured hashes
- Execute dictionary, brute-force, and rule-based attacks
- Create custom hashcat rules for targeted cracking
- Analyze password strength from cracking results
- Generate compliance reports on password policy effectiveness
- Benchmark GPU performance for hash cracking

## Key Concepts

This section covers key concepts for performing hash cracking with hashcat.

- Ensure all prerequisites are met before proceeding
- Follow the documented workflow steps in sequence
- Record results and any anomalies encountered during this phase
### Hashcat Attack Modes

| Mode | Flag | Description | Use Case |
|------|------|-------------|----------|
| Dictionary | -a 0 | Wordlist attack | Known password patterns |
| Combination | -a 1 | Combine two wordlists | Compound passwords |
| Brute-force | -a 3 | Mask-based enumeration | Short passwords |
| Rule-based | -a 0 -r | Dictionary + transformation rules | Complex variations |
| Hybrid | -a 6/7 | Wordlist + mask | Passwords with appended numbers |

### Common Hash Types

| Hash Mode | Type | Example Use |
|-----------|------|-------------|
| 0 | MD5 | Legacy web apps |
| 100 | SHA-1 | Legacy systems |
| 1000 | NTLM | Windows credentials |
| 1800 | sha512crypt | Linux /etc/shadow |
| 3200 | bcrypt | Modern web apps |
| 13100 | Kerberos TGS-REP | Active Directory |

## Security Considerations

- Only perform hash cracking with explicit written authorization
- Secure all captured hash data in transit and at rest
- Report all cracked passwords immediately to asset owners
- Use results to improve password policies, not exploit users
- Destroy cracked password data after engagement concludes
- Follow rules of engagement for penetration test scope

## Validation Criteria

- [ ] Hash type identification is correct
- [ ] Dictionary attack cracks weak passwords
- [ ] Rule-based attack cracks policy-compliant passwords
- [ ] Mask attack cracks short passwords
- [ ] Results report shows password strength distribution
- [ ] All operations performed within authorized scope
## When NOT to Use

- You don't have explicit written authorization to test
- Task is about defense/detection, not offense (use detection skills)
- You need to implement security controls (use implementing-* skills)
- Task requires compliance auditing (use auditing-* skills)
- You're investigating an incident (use incident response skills)
- Target is out of scope for your engagement
- Task is about vulnerability scanning only (use scanning tools)


## Red Flags

- Performing actions without explicit written authorization from the asset owner
- Testing against production systems without a defined scope and rules of engagement
- Exceeding the authorized scope of the engagement
- Leaving persistent access mechanisms without explicit approval
- Causing denial-of-service on production systems during testing
## Verification

- All steps executed successfully against a test environment before production use
- Output documented with screenshots or logs demonstrating expected behavior
- All exploited vulnerabilities documented with reproduction steps
- Scope boundaries confirmed — only authorized targets were tested
- Remediation recommendations included for every finding

## Process

```python
# Example: IOC detection
import re

IOC_PATTERNS = {
    "ip": r"\b(?:\d{1,3}\.){3}\d{1,3}\b",
    "domain": r"\b[a-z0-9-]+\.[a-z]{2,}\b",
    "hash_md5": r"\b[a-f0-9]{32}\b",
    "hash_sha256": r"\b[a-f0-9]{64}\b",
}

def extract_iocs(text: str) -> dict:
    return {k: re.findall(v, text) for k, v in IOC_PATTERNS.items()}
```

1. Analyze the task requirements
2. Apply domain expertise
3. Verify output quality

## Anti-Rationalization Table

| Rationalization | Reality |
|---|---|
| "We are too small to be targeted" | Automated attacks target everyone. Size does not matter. |
| "Security slows us down" | A breach slows you down 100x more. Build security in from the start. |
| "We will fix it after launch" | Vulnerabilities in production are exploited within hours. Fix before deploy. |