security-investigator: Skill for Claude Code

.github/skills/email-threat-posture/SKILL.md

email-threat-posture is a skill for Claude Code, Codex from SCStelz/security-investigator. It costs 156 tokens per session (9,894 once invoked), scanned A, original, MIT.

A guide for reporting on email threat protection in Microsoft Defender for Office 365, Microsoft's email security service. It analyzes mail flow, phishing, spam, malware, authentication checks, post-delivery cleanup, links, and attachments.

In plain words
What is it for?
Use it to report on email volume, phishing targets, DMARC, DKIM, SPF, and other authentication results, ZAP cleanup, Safe Links scans, and attachment threats.
Why use it?
It turns email security telemetry into a view of what threats were detected, blocked, delivered, or remediated and where protection may be weaker.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

This is SCStelz/security-investigator's own configuration. It tells Claude Code and Codex how to work on security-investigator itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything security-investigator configures →

Reuse

Borrowing it

Nothing to install: this file belongs to SCStelz/security-investigator. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/SCStelz/security-investigator/main/.github/skills/email-threat-posture/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/SCStelz/security-investigator

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 email-threat-posture

README.md
[![agentmods](https://agentmods.dev/badge/skills/scstelz/security-investigator/email-threat-posture/github.svg)](https://agentmods.dev/skills/scstelz/security-investigator/email-threat-posture)
Your own site
<a href="https://agentmods.dev/skills/scstelz/security-investigator/email-threat-posture"><img src="https://agentmods.dev/badge/skills/scstelz/security-investigator/email-threat-posture/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 email-threat-posture

Your own site · 80×15
<a href="https://agentmods.dev/skills/scstelz/security-investigator/email-threat-posture"><img src="https://agentmods.dev/badge/skills/scstelz/security-investigator/email-threat-posture.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 156 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 9,894 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 warn 7 Sept 2026
SkillSpector: 1 finding, up to medium

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 →

  • medium Agent Snooping · line 964
    Skill enumerates or reads other installed skills. Access to other skills' SKILL.md files or the skills directory reveals prompt instructions, capabilities, and secrets that should be invisible to peer skills.
    Fix: Remove all code or instructions that list or read other skills' files or directories. Skills should operate independently; cross-skill access is a privilege escalation.
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 $0.00156 $0.09894
Opus 5 $0.00078 $0.04947
Sonnet 5 $0.00031 $0.01979
Haiku 4.5 $0.00016 $0.00989

Measured 12d ago against content hash 6532e717a3cd, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

email-threat-posture 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.

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.

.github/skills/email-threat-posture/SKILL.md · 970 lines

How it starts

The opening of the file, as written. The whole thing — 970 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Email Threat Protection Posture — Instructions

Purpose

This skill generates an Email Threat Protection Posture Report using Microsoft Defender for Office 365 (MDO) telemetry available through Advanced Hunting. It provides C-level visibility into how effectively the organization's email security stack is detecting, blocking, and remediating email-based threats.

What this skill covers:

Domain Key Questions Answered
📬 Mail Flow Overview How many inbound emails? What's the daily trend? Who are the top senders?
🛡️ Threat Composition How many phishing, spam, and malware threats were detected?
🎯 Phishing Protection How many phishing emails were blocked vs delivered? Who are the most targeted users?
🔐 Email Authentication What are the DMARC/DKIM/SPF/CompAuth pass rates? Which domains fail authentication?
🧹 Post-Delivery Remediation How effective is ZAP? How many remediations succeeded vs failed?
🔗 Safe Links Protection How many URL clicks were scanned? Were any phishing clicks allowed through?
📎 Attachment Analysis What attachment types are flowing through email? Were any malicious?
📊 Detection Methods What detection technologies are catching threats (URL detonation, fingerprinting, etc.)?
📦 Delivery Disposition Where do emails end up — inbox, junk, quarantine, blocked?
🚨 MDO Incidents How many security incidents were generated by Defender for Office? What severity, status, and types?

Data sources: EmailEvents, EmailPostDeliveryEvents, UrlClickEvents, EmailAttachmentInfo, SecurityAlert, SecurityIncident (Advanced Hunting)

References:

Read the full file on GitHub · 970 lines

Files

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.

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 · 970 lines · 156 tokens per session scan A 6532e717a3cd

Subscribe to this mod's changes

email-threat-posture is a skill published in the GitHub repository SCStelz/security-investigator (245 stars, last pushed 4d ago), licensed MIT. It adds 156 tokens to every session and 9,894 once invoked, about $0.0008 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.

Related

Other skills, from other repositories

systematic-debugging

Use when encountering any bug, test failure, or unexpected behavior, before proposing fixes.

obra/superpowers · 21 tokens

local-ai-agents

Build local-first AI agents that run entirely on a developer workstation with Microsoft Foundry Local and Qwen function-calling models. Covers Small Language Models (SLMs), the OpenAI-compatible local endpoint, sandboxed local tools, local RAG with Chroma, local MCP servers, hybrid cloud/local routing, and the…

microsoft/ai-agents-for-beginners · 200 tokens

next-cache-components-adoption

Turn on Cache Components in a Next.js app and resolve the blocking routes it surfaces. Use when the user wants to enable, adopt, or migrate to Cache Components, flip the cacheComponents flag, work through a flood of blocking-prerender / instant validation errors, run the cache-components-instant-false codemod, or…

vercel/next.js · 95 tokens

insight-error-page

Write or audit an insight-kind error page for the Next.js dev overlay. Use when creating a new errors/ .mdx page, auditing an existing one, or checking that a page matches the framework fix cards. Covers page structure, title alignment, FixCard cards with Copy prompt button, code snippets, terminology verification…

vercel/next.js · 83 tokens

next-cache-components-optimizer

Drive a Next.js route to instant navigation by setting up an agentic loop, under Cache Components / PPR, on initial load (hard navigation) and client-side navigation (soft navigation). Encode the goal as a failing @next/playwright instant() e2e and work it to green, one verified route at a time; the shipped test then…

vercel/next.js · 170 tokens

next-partial-prefetching-adoption

Turn on Partial Prefetching in a Next.js app and work through the insights it surfaces. Use when the user wants to enable or adopt Partial Prefetching, flip the partialPrefetching flag, opt routes in with export const prefetch = 'partial', audit Link prefetch={true} behavior, preserve existing prefetched UI with…

vercel/next.js · 103 tokens