A guide to passive reconnaissance, meaning collecting public information about a target without directly contacting it. It covers subdomains, certificates, historical snapshots, technology fingerprints, and third-party assets.

Use it to inventory domains and services, find historical or third-party assets, record sources and timestamps, and prepare handoffs for testing or reporting.

It builds an evidence-based map of a public attack surface before active security testing begins.

osint-recon — Skill for Claude Code and Codex by xAmirHamza77

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 xAmirHamza77/ReverseOps-Skill --skill osint-recon

Clone the repo

git clone --depth 1 https://github.com/xAmirHamza77/ReverseOps-Skill

Made for: Claude Code, Codex.

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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/xamirhamza77/reverseops-skill/osint-recon/github.svg)](https://agentmods.dev/skills/xamirhamza77/reverseops-skill/osint-recon)

Your own site

<a href="https://agentmods.dev/skills/xamirhamza77/reverseops-skill/osint-recon"><img src="https://agentmods.dev/badge/skills/xamirhamza77/reverseops-skill/osint-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.

Your own site · 80×15

<a href="https://agentmods.dev/skills/xamirhamza77/reverseops-skill/osint-recon"><img src="https://agentmods.dev/badge/skills/xamirhamza77/reverseops-skill/osint-recon.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 91 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 1,053 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.

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.

Model	Per session	Once invoked
Fable 5.1	$0.00091	$0.01053
Opus 5	$0.00046	$0.00526
Sonnet 5	$0.00018	$0.00211
Haiku 4.5	$0.00009	$0.00105

Measured 6d ago against content hash 66879a15e1e2, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

osint-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 6d 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.target.com&output=json" | jq -r '.[].name_value' | sort -u

skills/osint-recon/SKILL.md · 98 lines

How it starts

The opening of the file, as written. The whole thing — 98 lines — stays where its author put it; the contents beside it link to each section on GitHub.

ACTION REQUIRED (execute immediately after reading)

NOW: confirm scope.md exists with auth.status=granted (passive recon still needs scope — the mapping output drives later ACT legality; see ../ops/scope-contract.md)
NOW: record network_profile in scope; during the passive phase only third-party data sources may be queried (crt.sh / Wayback / DNS / CA logs) — no direct contact with the target
NEXT: read ../tool-index.md for real paths of subfinder / amass / httpx / naabu; if missing, go through the bootstrap manifest
ACT: run the pipeline below; append every batch to the timeline + Evidence (../scripts/append-evidence.ps1)
ACT: land the asset inventory in work/<case>/attack-surface.md, then hand off to pentest-tools/ (active scanning) or reporting/ (dashboard + report)

osint-recon — passive recon & attack-surface mapping

Principles

Passive first: subdomains, certificates, snapshots, buckets, favicons — all from third-party sources, target sees nothing
Fully reproducible: every asset records its source and fetch time; everything enters the Evidence chain
Produce decision material only: asset list + priority + hypotheses. No "I ran every tool" noise.

Pipeline (in order — later stages consume earlier output)

1. Root asset confirmation

Action	Tools / sources	Output
WHOIS / ASN / netblock owner	`whois`, bgp.he.net, RDAP	org + ASN + CIDR list
Root domains & brand variants	cert CN/SAN, search engines, trademarks	root domains

2. Subdomain enumeration (passive)

subfinder -d target.com -all -silent -o subs.txt
amass enum -passive -d target.com -o amass.txt
curl -s "https://crt.sh/?q=%25.target.com&output=json" | jq -r '.[].name_value' | sort -u

Dedupe and merge → subs.all.txt. Resolve only, do not probe.

3. History & exposure

Source	What to look for
Wayback Machine CDX	endpoints that are down but not decommissioned, legacy parameters, backup paths
GitHub / GitLab code search	leaked tokens, internal hostnames, CI configs (dork on the in-scope org name)
Certificate transparency logs	naming patterns for staging / dev / vpn
Public buckets / storage	`s3://<brand>-*` name guessing + public indexes (HEAD/GET public objects only)

Read the full file on GitHub · 98 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.

6d ago First seen · 98 lines · 91 tokens per session scan A 66879a15e1e2

Subscribe to this mod's changes

osint-recon is a skill published in the GitHub repository xAmirHamza77/ReverseOps-Skill (4 stars, last pushed 1mo ago), licensed MIT. It adds 91 tokens to every session and 1,053 once invoked, about $0.0005 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 2026-09-03.

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