recon-osint

recon-osint is a skill for Claude Code from hypnguyen1209/offensive-claude. It costs 74 tokens per session (2,505 once invoked), scanned A, original, MIT.

A reconnaissance and open-source intelligence guide for mapping an organization’s internet-facing systems and publicly available information. It covers domains, cloud assets, exposed secrets, leaked credentials, and relevant vulnerabilities.

In plain words
What is it for?
Finding subdomains, IP ranges, DNS records, cloud resources, possible subdomain takeovers, public repository secrets, breach information, and high-priority CVEs.
Why use it?
It helps security testers build a fuller picture of a target instead of checking only the first known website or server. It also helps prioritize vulnerabilities based on exposure and known exploitation risk.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the offensive-claude plugin — 30 skills, 18 commands, 8 agents, 1 hook shipped together

Good fit Finding subdomains, IP ranges, DNS records, cloud resources, possible subdomain takeovers, public repository secrets, breach information, and high-priority CVEs.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/hypnguyen1209/offensive-claude/recon-osint
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 hypnguyen1209/offensive-claude --skill recon-osint
Clone the repo
git clone --depth 1 https://github.com/hypnguyen1209/offensive-claude

Made for: Claude Code.

Or install offensive-claude, the plugin that ships this one along with the rest of its 30 skills, 18 commands, 8 agents, 1 hook.

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-osint

README.md
[![agentmods](https://agentmods.dev/badge/skills/hypnguyen1209/offensive-claude/recon-osint/github.svg)](https://agentmods.dev/skills/hypnguyen1209/offensive-claude/recon-osint)
Your own site
<a href="https://agentmods.dev/skills/hypnguyen1209/offensive-claude/recon-osint"><img src="https://agentmods.dev/badge/skills/hypnguyen1209/offensive-claude/recon-osint/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-osint

Your own site · 80×15
<a href="https://agentmods.dev/skills/hypnguyen1209/offensive-claude/recon-osint"><img src="https://agentmods.dev/badge/skills/hypnguyen1209/offensive-claude/recon-osint.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 2,505 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. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
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 $0.02505
Opus 5 $0.00037 $0.01252
Sonnet 5 $0.00015 $0.00501
Haiku 4.5 $0.00007 $0.00250

Measured 12d ago against content hash ea057299a384, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

recon-osint 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 12d ago.

The scan reads SKILL.md. This mod also ships 8 executable files (scripts/breach_intel.py, scripts/cloud_asset_enum.py, scripts/cve_prioritizer.py, …), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

skills/recon-osint/SKILL.md · 115 lines

How it starts

The opening of the file, as written. The whole thing — 115 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Reconnaissance & OSINT

When to Activate

  • A new engagement begins and you need a full external attack-surface map for a set of root domains / ASNs.
  • Expanding scope: pivoting from one discovered asset (subdomain, IP block, cloud account) to the rest of the estate.
  • Hunting dangling DNS / subdomain-takeover candidates, including S3 buckets referenced by CI/CD assets.
  • Building a target profile for social engineering / initial access (emails, usernames, breach + infostealer exposure).
  • Discovering leaked secrets in public GitHub/GitLab orgs and exposed cloud storage.
  • Triaging which discovered CVEs actually matter (KEV + EPSS + exposure) before weaponization.

Technique Map

Technique ATT&CK CWE Reference Script
Passive subdomain enum (subfinder/amass/CT logs) T1590.002, T1596.001 CWE-200 references/subdomain-discovery.md scripts/recon_orchestrator.py
DNS brute / permutation / resolution (puredns/alterx/dnsx) T1595.002, T1590.002 CWE-200 references/subdomain-discovery.md scripts/recon_orchestrator.py
ASN → CIDR → reverse-DNS expansion T1590.005, T1596.005 CWE-200 references/subdomain-discovery.md scripts/recon_orchestrator.py
HTTP probing + tech fingerprint (httpx) T1595.002, T1592.002 CWE-200 references/attack-surface-mapping.md scripts/recon_orchestrator.py
Headless crawling + archive URLs (katana/gau) T1595.002, T1593.003 CWE-200 references/attack-surface-mapping.md scripts/js_secret_hunter.py
JavaScript endpoint / secret extraction T1593.003, T1552.001 CWE-540 references/attack-surface-mapping.md scripts/js_secret_hunter.py
Subdomain takeover (dangling CNAME/NS) T1583.001, T1584.001 CWE-350 references/subdomain-takeover.md scripts/subdomain_takeover.py
Deleted-S3 takeover → supply-chain pivot T1583.001, T1195.002 CWE-350 references/subdomain-takeover.md scripts/subdomain_takeover.py
Multi-cloud bucket/blob enum (cloud_enum) T1580, T1596.005 CWE-732 references/cloud-saas-recon.md scripts/cloud_asset_enum.py
Azure tenant outsider recon (AADInternals) T1590.001, T1589 CWE-200 references/cloud-saas-recon.md scripts/cloud_asset_enum.py
GitHub/GitLab dorking + secret scanning T1593.003, T1213.003 CWE-540 references/cloud-saas-recon.md scripts/cloud_asset_enum.py
Email/username harvesting (theHarvester) T1589.002, T1591 CWE-200 references/breach-credential-intel.md scripts/breach_intel.py
Breach + infostealer credential intel (HIBP/DeHashed) T1589.001, T1596 CWE-522 references/breach-credential-intel.md scripts/breach_intel.py
CVE enrichment + prioritization (NVD/EPSS/KEV) T1592.002, T1596 CWE-1395 references/cve-exploit-intel.md scripts/cve_prioritizer.py
Shodan InternetDB exposure → CVE mapping T1596.005, T1595.002 CWE-200 references/cve-exploit-intel.md scripts/cve_prioritizer.py

Read the full file on GitHub · 115 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 · 115 lines · 74 tokens per session scan A ea057299a384

Subscribe to this mod's changes

recon-osint is a skill published in the GitHub repository hypnguyen1209/offensive-claude (357 stars, last pushed 25d ago), licensed MIT. It adds 74 tokens to every session and 2,505 once invoked, about $0.0004 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 2026-08-30.

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