How do I install the John skill?

Run npx skillmds@latest add aeondave/john in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

This skill has not completed SkillMD's automated safety review yet. SkillMD never runs a skill's scripts for you; review the SKILL.md before installing.

Which AI agents work with John?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Yes. Installing skills from SkillMD is free. This skill is licensed under MIT.

AeonDave (@aeondave) published this skill. Their other Agent Skills are listed on their SkillMD profile.

John by aeondave — Agent Skill

Name: John
Author: AeonDave

File contents

John the Ripper

CPU password cracker — hundreds of hash formats, wordlist + rules + incremental.

Quick Start

# Auto-detect format and crack
john hashes.txt --wordlist=/usr/share/wordlists/rockyou.txt

# Show cracked passwords
john hashes.txt --show

# Single crack mode (fast, username-based)
john hashes.txt --single

# Incremental (brute-force)
john hashes.txt --incremental

Core Flags

Flag	Purpose
`--wordlist=FILE`	Dictionary attack
`--rules[=RULE]`	Apply mangling rules
`--format=TYPE`	Force hash format
`--single`	Single crack (username hints)
`--incremental`	Brute-force
`--show`	Display cracked passwords
`--pot=FILE`	Custom pot file
`--fork=N`	Parallel processes
`--list=formats`	List all formats

Common Workflows

NTLM with rules:

john ntlm.txt --format=NT --wordlist=rockyou.txt --rules=best64

SSH private key:

ssh2john id_rsa > id_rsa.hash
john id_rsa.hash --wordlist=rockyou.txt

Zip archive:

zip2john archive.zip > zip.hash
john zip.hash --wordlist=rockyou.txt

PDF:

pdf2john document.pdf > pdf.hash
john pdf.hash --wordlist=rockyou.txt

KeePass database:

keepass2john database.kdbx > kp.hash
john kp.hash --wordlist=rockyou.txt

Office documents (docx/xlsx):

office2john document.docx > office.hash
john office.hash --wordlist=rockyou.txt

7-Zip:

7z2john archive.7z > 7z.hash
john 7z.hash --wordlist=rockyou.txt

Session Management

# Named session
john hashes.txt --wordlist=rockyou.txt --session=mysession

# Resume
john --restore=mysession

# Check status of running session (send USR1 signal or press 'q')
john --status=mysession

Parallel Cracking

# Fork N processes (uses all CPU cores)
john hashes.txt --wordlist=rockyou.txt --fork=4

Custom Rules (inline in john.conf)

[List.Rules:MyRules]
# Append year variants
Az"[0-9][0-9][0-9][0-9]"
# Capitalize first + append !
c Az"!"
# l33t substitutions
sa@ se3 si1 so0

john hashes.txt --wordlist=rockyou.txt --rules=MyRules

Resources

File	When to load
`references/formats-and-rules.md`	Supported format names, *2john tool list, rule syntax reference

---name: johndescription: Auth/lab ref: CPU-based password cracker supporting hundreds of hash formats with wordlist, rules, and incremental modes.license: MIT---# John the RipperCPU password cracker — hundreds of hash formats, wordlist + rules + incremental.## Quick Start```bash# Auto-detect format and crackjohn hashes.txt --wordlist=/usr/share/wordlists/rockyou.txt# Show cracked passwordsjohn hashes.txt --show# Single crack mode (fast, username-based)john hashes.txt --single# Incremental (brute-force)john hashes.txt --incremental```## Core Flags| Flag | Purpose ||------|---------|| `--wordlist=FILE` | Dictionary attack || `--rules[=RULE]` | Apply mangling rules || `--format=TYPE` | Force hash format || `--single` | Single crack (username hints) || `--incremental` | Brute-force || `--show` | Display cracked passwords || `--pot=FILE` | Custom pot file || `--fork=N` | Parallel processes || `--list=formats` | List all formats |## Common Workflows**NTLM with rules:**```bashjohn ntlm.txt --format=NT --wordlist=rockyou.txt --rules=best64```**SSH private key:**```bashssh2john id_rsa > id_rsa.hashjohn id_rsa.hash --wordlist=rockyou.txt```**Zip archive:**```bashzip2john archive.zip > zip.hashjohn zip.hash --wordlist=rockyou.txt```**PDF:**```bashpdf2john document.pdf > pdf.hashjohn pdf.hash --wordlist=rockyou.txt```**KeePass database:**```bashkeepass2john database.kdbx > kp.hashjohn kp.hash --wordlist=rockyou.txt```**Office documents (docx/xlsx):**```bashoffice2john document.docx > office.hashjohn office.hash --wordlist=rockyou.txt```**7-Zip:**```bash7z2john archive.7z > 7z.hashjohn 7z.hash --wordlist=rockyou.txt```## Session Management```bash# Named sessionjohn hashes.txt --wordlist=rockyou.txt --session=mysession# Resumejohn --restore=mysession# Check status of running session (send USR1 signal or press 'q')john --status=mysession```## Parallel Cracking```bash# Fork N processes (uses all CPU cores)john hashes.txt --wordlist=rockyou.txt --fork=4```## Custom Rules (inline in john.conf)```ini[List.Rules:MyRules]# Append year variantsAz"[0-9][0-9][0-9][0-9]"# Capitalize first + append !c Az"!"# l33t substitutionssa@ se3 si1 so0``````bashjohn hashes.txt --wordlist=rockyou.txt --rules=MyRules```## Resources| File | When to load ||------|--------------|| `references/formats-and-rules.md` | Supported format names, *2john tool list, rule syntax reference |

Frequently asked questions

John