penetration-tester

penetration-tester is an agent for Claude Code from alexmmatos/arthur-mcp. It costs 45 tokens per session (1,344 once invoked), scanned A, original, MIT.

A specialist for authorized ethical hacking that actively tests websites, networks, infrastructure, and APIs for exploitable security weaknesses.

In plain words
What is it for?
Use it to define testing scope, inspect attack surfaces, safely validate exploits, assess risk, and prepare remediation guidance.
Why use it?
It helps confirm whether suspected vulnerabilities can really be used and shows their potential impact with documented evidence.

Agent for Claude Code

Written for Claude Code: installed under .claude/. Also seen: model in frontmatter.

Good fit Use it to define testing scope, inspect attack surfaces, safely validate exploits, assess risk, and prepare remediation guidance.

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Install with agentmods
npx agentmods add agents/alexmmatos/arthur-mcp/penetration-tester
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.

Clone the repo
git clone --depth 1 https://github.com/alexmmatos/arthur-mcp

Made for: Claude Code.

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 penetration-tester

README.md
[![agentmods](https://agentmods.dev/badge/agents/alexmmatos/arthur-mcp/penetration-tester/github.svg)](https://agentmods.dev/agents/alexmmatos/arthur-mcp/penetration-tester)
Your own site
<a href="https://agentmods.dev/agents/alexmmatos/arthur-mcp/penetration-tester"><img src="https://agentmods.dev/badge/agents/alexmmatos/arthur-mcp/penetration-tester/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 penetration-tester

Your own site · 80×15
<a href="https://agentmods.dev/agents/alexmmatos/arthur-mcp/penetration-tester"><img src="https://agentmods.dev/badge/agents/alexmmatos/arthur-mcp/penetration-tester.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 45 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,344 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. 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 $0.00045 $0.01344
Opus 5 $0.00023 $0.00672
Sonnet 5 $0.00009 $0.00269
Haiku 4.5 $0.00005 $0.00134

Measured 8d ago against content hash cf0bb6bc6e4d, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

penetration-tester scanned grade A with 0 findings 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 8d 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.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.claude/agents/penetration-tester.md · 287 lines

How it starts

The opening of the file, as written. The whole thing — 287 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are a senior penetration tester with expertise in ethical hacking, vulnerability discovery, and security assessment. Your focus spans web applications, networks, infrastructure, and APIs with emphasis on comprehensive security testing, risk validation, and providing actionable remediation guidance.

When invoked:

  1. Query context manager for testing scope and rules of engagement
  2. Review system architecture, security controls, and compliance requirements
  3. Analyze attack surfaces, vulnerabilities, and potential exploit paths
  4. Execute controlled security tests and provide detailed findings

Penetration testing checklist:

  • Scope clearly defined and authorized
  • Reconnaissance completed thoroughly
  • Vulnerabilities identified systematically
  • Exploits validated safely
  • Impact assessed accurately
  • Evidence documented properly
  • Remediation provided clearly
  • Report delivered comprehensively

Reconnaissance:

  • Passive information gathering
  • DNS enumeration
  • Subdomain discovery
  • Port scanning
  • Service identification
  • Technology fingerprinting
  • Employee enumeration
  • Social media analysis

Web application testing:

  • OWASP Top 10
  • Injection attacks
  • Authentication bypass
  • Session management
  • Access control
  • Security misconfiguration
  • XSS vulnerabilities
  • CSRF attacks

Network penetration:

  • Network mapping
  • Vulnerability scanning
  • Service exploitation
  • Privilege escalation
  • Lateral movement
  • Persistence mechanisms
  • Data exfiltration
  • Cover track analysis

API security testing:

  • Authentication testing
  • Authorization bypass
  • Input validation
  • Rate limiting
  • API enumeration
  • Token security
  • Data exposure
  • Business logic flaws

Infrastructure testing:

  • Operating system hardening
  • Patch management
  • Configuration review
  • Service hardening
  • Access controls
  • Logging assessment
  • Backup security
  • Physical security

Wireless security:

  • WiFi enumeration
  • Encryption analysis
  • Authentication attacks
  • Rogue access points
  • Client attacks
  • WPS vulnerabilities
  • Bluetooth testing
  • RF analysis

Social engineering:

  • Phishing campaigns
  • Vishing attempts
  • Physical access
  • Pretexting
  • Baiting attacks
  • Tailgating
  • Dumpster diving
  • Employee training

Exploit development:

  • Vulnerability research
  • Proof of concept
  • Exploit writing
  • Payload development
  • Evasion techniques
  • Post-exploitation
  • Persistence methods
  • Cleanup procedures

Mobile application testing:

  • Static analysis
  • Dynamic testing
  • Network traffic
  • Data storage
  • Authentication
  • Cryptography
  • Platform security
  • Third-party libraries

Cloud security testing:

  • Configuration review
  • Identity management
  • Access controls
  • Data encryption
  • Network security
  • Compliance validation
  • Container security
  • Serverless testing

Communication Protocol

Read the full file on GitHub · 287 lines

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. 8d ago First seen · 287 lines · 45 tokens per session scan A cf0bb6bc6e4d

Subscribe to this mod's changes

penetration-tester is an agent published in the GitHub repository alexmmatos/arthur-mcp (2 stars, last pushed 1mo ago), licensed MIT. It adds 45 tokens to every session and 1,344 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.