recon

recon is a skill for Claude Code from briiirussell/cybersecurity-skills. It costs 74 tokens per session (1,002 once invoked), scanned A, original, MIT.

Instructions for reconnaissance, the process of discovering and organizing a target’s exposed systems and services during an authorized security test.

In plain words
What is it for?
Use them for asset discovery, DNS and subdomain checks, port scanning, service identification, and building an attack-surface map for a penetration test, bug bounty, or CTF.
Why use it?
They provide a structured way to map what exists before testing for weaknesses, while requiring permission and a defined scope.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter.

Part of the cybersecurity-skills plugin — 28 skills shipped together

Good fit Use them for asset discovery, DNS and subdomain checks, port scanning, service identification, and building an attack-surface map for a penetration test, bug bounty, or CTF.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/briiirussell/cybersecurity-skills/recon
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 briiirussell/cybersecurity-skills --skill recon
Clone the repo
git clone --depth 1 https://github.com/briiirussell/cybersecurity-skills

Made for: Claude Code.

Or install cybersecurity-skills, the plugin that ships this one along with the rest of its 28 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 recon

README.md
[![agentmods](https://agentmods.dev/badge/skills/briiirussell/cybersecurity-skills/recon/github.svg)](https://agentmods.dev/skills/briiirussell/cybersecurity-skills/recon)
Your own site
<a href="https://agentmods.dev/skills/briiirussell/cybersecurity-skills/recon"><img src="https://agentmods.dev/badge/skills/briiirussell/cybersecurity-skills/recon/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 recon

Your own site · 80×15
<a href="https://agentmods.dev/skills/briiirussell/cybersecurity-skills/recon"><img src="https://agentmods.dev/badge/skills/briiirussell/cybersecurity-skills/recon.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 74 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,002 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 1 finding, up to high

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • high YARA Match · line 49
    YARA rule matched a hack tool or exploit indicator (offensive tools, reconnaissance, privilege escalation, or exploit frameworks).
    Fix: Remove offensive tool references and exploit code. Legitimate agent skills should not contain penetration testing tools, exploit frameworks, or reconnaissance utilities.
How audits are shown
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 $0.00074 $0.01002
Opus 5 $0.00037 $0.00501
Sonnet 5 $0.00015 $0.00200
Haiku 4.5 $0.00007 $0.00100

Measured 12d ago against content hash 380c788913c7, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

recon scanned grade A 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 12d 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.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

curl -s "https://crt.sh/?q=%25.$ARGUMENTS&output=json" | jq -r '.[].name_value' | sort -u
skills/recon/SKILL.md · 114 lines

How it starts

The opening of the file, as written. The whole thing — 114 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Recon — Penetration Testing Reconnaissance

Perform structured reconnaissance against an authorized target, organizing findings into an actionable attack surface map.

Cross-references: osint-recon for the deeper open-source-intelligence pass (people, organizations, historical data) — this skill is the active/passive target-mapping side, osint-recon is the broader investigative side; they pair naturally. web-pentest for the next stage once recon has produced an attack surface map and an authorized target list. owasp-audit for source-code review when you have access to the target's code.

Authorization Check

Before running any commands, confirm:

  1. The user has written authorization for the target (pentest engagement, bug bounty program, CTF/lab environment)
  2. The target is within the defined scope

If authorization is unclear, ask before proceeding. Never assume authorization.

Methodology

Phase 1: Passive Recon

Gather information without touching the target directly.

DNS enumeration:

  • Run dig any $ARGUMENTS for A, AAAA, MX, TXT, NS, CNAME records
  • Attempt zone transfer: dig axfr @ns-server $ARGUMENTS
  • Enumerate subdomains via certificate transparency:
    curl -s "https://crt.sh/?q=%25.$ARGUMENTS&output=json" | jq -r '.[].name_value' | sort -u
    

WHOIS and registration: Run whois $ARGUMENTS for registrant, nameserver, and creation date info.

Search engine dorking: Use targeted queries — site:, inurl:, filetype:, intitle: — to find exposed pages, documents, and admin panels.

Technology fingerprinting: Identify frameworks, CMS, server software, and JavaScript libraries from public-facing pages.

Public code repositories: Search GitHub/GitLab for the target's org name, domain, API keys, or internal paths.

Historical data: Check the Wayback Machine for old endpoints, removed pages, and configuration files.

Phase 2: Active Recon (explicit authorization only)

Port scanning:

nmap -sC -sV -oN scan-results.txt $ARGUMENTS

Start with top 1000 ports. Expand to full range (-p-) if needed. Use -Pn if the host appears down but is in scope.

Read the full file on GitHub · 114 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. 12d ago First seen · 114 lines · 74 tokens per session scan A 380c788913c7

Subscribe to this mod's changes

recon is a skill published in the GitHub repository briiirussell/cybersecurity-skills (387 stars, last pushed 3mo ago), licensed MIT. It adds 74 tokens to every session and 1,002 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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