passive-recon

passive-recon is a skill for Claude Code, Codex from jinyimeng01/mastermind-bug-bounty. It costs 50 tokens per session (941 once invoked), scanned A, original, no licence file.

A guide to passive reconnaissance, which gathers publicly available information about a system without contacting the target directly. It covers domains, IP addresses, technologies, historical URLs, and registration data.

In plain words
What is it for?
Use it to find subdomains, DNS history, IP intelligence, technology clues from favicons, old URLs from the Wayback Machine, and WHOIS records.
Why use it?
It helps build a picture of a target's public footprint while avoiding direct interaction with its systems.

Skill for Claude CodeCodex

Which agent this was written for is unclear — body not stored (licence); the path alone says nothing.

Good fit Use it to find subdomains, DNS history, IP intelligence, technology clues from favicons, old URLs from the Wayback Machine, and WHOIS records.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/jinyimeng01/mastermind-bug-bounty/passive_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 jinyimeng01/mastermind-bug-bounty --skill passive_recon
Clone the repo
git clone --depth 1 https://github.com/jinyimeng01/mastermind-bug-bounty

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.

agentmods badge for passive-recon

README.md
[![agentmods](https://agentmods.dev/badge/skills/jinyimeng01/mastermind-bug-bounty/passive_recon/github.svg)](https://agentmods.dev/skills/jinyimeng01/mastermind-bug-bounty/passive_recon)
Your own site
<a href="https://agentmods.dev/skills/jinyimeng01/mastermind-bug-bounty/passive_recon"><img src="https://agentmods.dev/badge/skills/jinyimeng01/mastermind-bug-bounty/passive_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 passive-recon

Your own site · 80×15
<a href="https://agentmods.dev/skills/jinyimeng01/mastermind-bug-bounty/passive_recon"><img src="https://agentmods.dev/badge/skills/jinyimeng01/mastermind-bug-bounty/passive_recon.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 50 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 941 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 unknown 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 $0.00050 $0.00941
Opus 5 $0.00025 $0.00470
Sonnet 5 $0.00010 $0.00188
Haiku 4.5 $0.00005 $0.00094

Measured 10d ago against content hash 0e0e92c33973, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

passive-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 10d 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}&output=json" | \
skills/passive_recon/SKILL.md · 113 lines

The source is not reproduced here

No licence file

A repository with no LICENSE is all rights reserved by default, so the body is not copied here. The metadata, the measurements and the link are.

Read it on GitHub

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. 10d ago First seen · 113 lines · 50 tokens per session scan A 0e0e92c33973

Subscribe to this mod's changes

passive-recon is a skill published in the GitHub repository jinyimeng01/mastermind-bug-bounty (57 stars, last pushed 2mo ago), with no licence file. It adds 50 tokens to every session and 941 once invoked, about $0.0003 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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