Claude-OSINT is a library of structured skills that guide Claude through external reconnaissance, including methodology, attack-surface analysis, security checks, risk assessment, and related investigative techniques. It is intended for authorized red-team and bug-bounty engagements. The catalogue entries are the project's own Claude skills for these reconnaissance workflows.
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.
npx skills add elementalsouls/Claude-OSINT --skill email-domain-securitygit clone --depth 1 https://github.com/elementalsouls/Claude-OSINTWrote 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.
[](https://agentmods.dev/skills/elementalsouls/claude-osint/email-domain-security)<a href="https://agentmods.dev/skills/elementalsouls/claude-osint/email-domain-security"><img src="https://agentmods.dev/badge/skills/elementalsouls/claude-osint/email-domain-security/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.
<a href="https://agentmods.dev/skills/elementalsouls/claude-osint/email-domain-security"><img src="https://agentmods.dev/badge/skills/elementalsouls/claude-osint/email-domain-security.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector warn
SkillSpector: 2 findings, 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 Output Handling · line 367 Model output is used without validation or sanitization. Unvalidated output injected into downstream contexts (SQL, shell, HTML) enables injection attacks and arbitrary code execution.Fix: Validate and sanitize all model output before using it in downstream contexts. Use parameterized queries for SQL, shell quoting for commands, and HTML encoding for web output.
- high Anti-Refusal · line 455 Skill instructs the agent to omit warnings, disclaimers, or ethical commentary. Stripping safety caveats hides risk from the user and is a common jailbreak preamble.Fix: Remove instructions that suppress warnings, disclaimers, or ethical commentary. Let the agent surface safety-relevant caveats to the user.
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 | $0.00362 | $0.11697 |
| Opus 5 | $0.00181 | $0.05849 |
| Sonnet 5 | $0.00072 | $0.02339 |
| Haiku 4.5 | $0.00036 | $0.01170 |
Grade A, and why
email-domain-security 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.
Runs shell commandslowCapability
Expected in a hook, worth knowing in a rule or an instructions file.
out = subprocess.run( How it starts
The opening of the file, as written. The whole thing — 609 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Email Domain Security — Spoofability Verdict & SPF Supply-Chain Analysis
Companion skills:
offensive-osint§16.14 (raw record-fetch recipes — dig/PowerShell one-liners for SPF/DMARC/DKIM/BIMI/MTA-STS/TLS-RPT/DNSSEC/CAA, the MX→IdP inference table, the DMARC reporting-vendor table).osint-methodology(confidence levels, output format, severity rubric this skill inherits). Fetch the records with §16.14 first; bring the raw TXT text here for the verdict. This skill does not re-list what a record is — it reasons about what a domain's combination of records actually lets an attacker do.
0. When to Use / When NOT
Use this skill when:
- Asked to audit spoof feasibility, produce an email-spoofability verdict, or explain "is domain X spoofable."
- You already have raw SPF/DMARC TXT text (via
offensive-osint§16.14 or your owndig) and need the verdict, not just the record dump. - Investigating an SPF PermError, a long or unusual include chain, or a dead
include:target. - Writing a client-facing finding that has to survive the pushback "we have SPF
-all, why is this flagged?" - Reasoning about DMARC subdomain policy inheritance,
pct=partial enforcement, or duplicate-record handling.
Do NOT use this skill when:
- You haven't fetched the raw records yet. Run
offensive-osint§16.14's dig/PowerShell recipes first, then bring the text here. - You want to actually send a spoofed test message or run an SMTP
RCPT TOliveness check. That is active engagement work requiring explicit authorization and is out of scope for this passive-DNS skill — see §14. - You're auditing TLS/cert posture rather than email auth — that's
offensive-osint§16.15 / TLS deep audit territory. - You need AXFR / zone-transfer analysis.
dns_deep-class modules run that check alongside the email-auth sweep, but it's a distinct DNS finding (open zone transfer, unrelated to spoofability) — see the note in §9.
1. Scope & Authorization Posture
Same posture as the companion skills: assets you own or have written authorization to assess. Everything in this skill is passive — reading published, public DNS TXT records that any resolver on the internet can already see — so it carries essentially zero detectability risk on its own.
What ships with it
1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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.
- 10d ago First seen · 609 lines · 362 tokens per session scan A 47dfa12c7dff
email-domain-security is a skill published in the GitHub repository elementalsouls/Claude-OSINT (2,583 stars, last pushed 10d ago), licensed MIT. It adds 362 tokens to every session and 11,697 once invoked, about $0.0018 per session on Opus 5. A static security scan graded it A with 1 finding (runs shell commands). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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