cracking-passwords

cracking-passwords is a skill for Claude Code from trilwu/secskills. It costs 41 tokens per session (3,561 once invoked), scanned C, original, MIT.

A guide to testing password-based access, including identifying and cracking password hashes, guessing online passwords, spraying one password across accounts, and using recovered password material. A hash is a one-way representation of a password.

In plain words
What is it for?
Use it in authorized assessments to analyze password hashes, build wordlists, run offline cracking, test spraying safeguards, and assess pass-the-hash exposure.
Why use it?
It helps reveal weak or reused passwords and shows how credential attacks could affect accounts and connected systems.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin. Also seen: positional $N argument.

Part of the secskills-offense plugin — 40 skills shipped together

Good fit Use it in authorized assessments to analyze password hashes, build wordlists, run offline cracking, test spraying safeguards, and assess pass-the-hash exposure.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/trilwu/secskills/cracking-passwords
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add trilwu/secskills --skill cracking-passwords
Clone the repo
git clone --depth 1 https://github.com/trilwu/secskills

Made for: Claude Code.

Or install secskills-offense, the plugin that ships this one along with the rest of its 40 skills.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for cracking-passwords

README.md
[![agentmods](https://agentmods.dev/badge/skills/trilwu/secskills/cracking-passwords/github.svg)](https://agentmods.dev/skills/trilwu/secskills/cracking-passwords)
Your own site
<a href="https://agentmods.dev/skills/trilwu/secskills/cracking-passwords"><img src="https://agentmods.dev/badge/skills/trilwu/secskills/cracking-passwords/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for cracking-passwords

Your own site · 80×15
<a href="https://agentmods.dev/skills/trilwu/secskills/cracking-passwords"><img src="https://agentmods.dev/badge/skills/trilwu/secskills/cracking-passwords.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 41 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,561 The whole file, excluding the scripts and references it only reads on demand.
Security scan C 1 finding. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00041 $0.03561
Opus 5 $0.00020 $0.01781
Sonnet 5 $0.00008 $0.00712
Haiku 4.5 $0.00004 $0.00356

Measured 5d ago against content hash 76b9a79a8201, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade C, and why

cracking-passwords scanned grade C with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 5d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Reaches for credential fileshighPrivilege escalation

SSH keys, cloud credentials, git-credentials, .npmrc, /etc/shadow: reading these is how a config file becomes a credential leak.

- [T1003.008](https://attack.mitre.org/techniques/T1003/008/) /etc/passwd and /etc/shadow — see also `escalating-linux-privileges`
Origin

Copies of this mod

1 near-identical copy found in the catalogue:

secskills-offense/skills/cracking-passwords/SKILL.md · 466 lines

How it starts

The opening of the file, as written. The whole thing — 466 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Password Attacks and Credential Cracking Skill

You are a password cracking and credential attack expert. Use this skill when the user requests help with:

  • Password hash cracking (hashcat, john)
  • Hash identification and extraction
  • Credential spraying and brute forcing
  • Rainbow table attacks
  • Pass-the-hash techniques
  • Wordlist generation
  • Rule-based attacks

When to Use

Activate this skill when the user asks to:

  • Crack password hashes
  • Identify unknown hash types
  • Perform password spraying
  • Generate wordlists
  • Optimize hashcat/john performance
  • Extract and crack credentials
  • Perform pass-the-hash attacks
  • Help with credential-based attacks

Scope and authorization. Cracking is only as authorized as the hashes were. Confirm the material came from a system in scope, and treat recovered plaintext as live credentials — encrypt at rest, never paste into a shared doc or a third-party cracking service, and destroy it at engagement end per the contracted retention terms.

Three domain-specific traps:

  • Spraying is an availability risk, not just an access one. Online attempts against production auth can lock out real accounts and page a real SOC. You need the lockout threshold and observation window in writing, an agreed attempt rate, and a named contact — or you cause an outage and a false incident.
  • Breach-corpus material is not fair game by default. Third-party dump data belongs to people who are not your client. Using it to seed wordlists or validate reuse against live accounts needs explicit engagement coverage and a lawful basis under GDPR-style regimes.
  • Pass-the-hash is authentication, not analysis. Replaying a hash is unauthorized access unless lateral movement is explicitly in scope.

Report the fact of a weak credential and its policy implication; there is rarely a reason to put recovered plaintext in a deliverable.

When NOT to Use

  • Online brute force against a live service — that is testing, not cracking; use testing-web-applications or enumerating-network-services, and mind lockouts
  • Obtaining the hashes in the first place — use the relevant privilege escalation or attacking-active-directory skill
  • Reviewing how an application stores passwords — use reviewing-cryptography

Read the full file on GitHub · 466 lines

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 5d ago First seen · 466 lines · 41 tokens per session scan C 76b9a79a8201

Subscribe to this mod's changes

cracking-passwords is a skill published in the GitHub repository trilwu/secskills (137 stars, last pushed 4d ago), licensed MIT. It adds 41 tokens to every session and 3,561 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it C with 1 finding (reaches for credential files). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.

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