email-security

email-security is a skill for Claude Code, Codex from Asaiuta/reverse-workbench-skill. It costs 35 tokens per session (470 once invoked), scanned A, original, MIT.

An authorized workflow for examining suspicious email, including its technical headers, links, attachments, sender authentication, and mailbox or tenant settings.

In plain words
What is it for?
It helps analyze phishing samples, review SPF, DKIM, and DMARC email authentication, identify indicators of compromise, assess OAuth or mailbox-token abuse, and design approved security-awareness exercises.
Why use it?
Phishing and business-email-compromise messages can look genuine, while their real origin and risks are often hidden in headers, links, attachments, or account permissions.

Skill for Claude CodeCodex

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.

agentmods
npx agentmods add skills/asaiuta/reverse-workbench-skill/email-security
Any agent
npx skills add Asaiuta/reverse-workbench-skill --skill email-security
Clone the repo
git clone --depth 1 https://github.com/Asaiuta/reverse-workbench-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.

agentmods badge for email-security

README.md
[![agentmods](https://agentmods.dev/badge/skills/asaiuta/reverse-workbench-skill/email-security.svg)](https://agentmods.dev/skills/asaiuta/reverse-workbench-skill/email-security)
Your own site
<a href="https://agentmods.dev/skills/asaiuta/reverse-workbench-skill/email-security"><img src="https://agentmods.dev/badge/skills/asaiuta/reverse-workbench-skill/email-security.svg" alt="Measured on agentmods" height="20"></a>
Per session 35 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 470 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00035 $0.00470
Opus 5 $0.00017 $0.00235
Sonnet 5 $0.00007 $0.00094
Haiku 4.5 $0.00003 $0.00047

Measured 3d ago against content hash fb8815157759, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

email-security 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 3d 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.

Origin

Copies of this mod

1 near-identical copy found in the catalogue:

skills/email-security/SKILL.md · 55 lines

What it actually says

Email Security & Phishing Analysis

ACTION REQUIRED(读完后立刻执行)

  1. NOW: 确认授权(分析样本邮件 / 租户配置评审)
  2. NOW: 不向真实用户二次投递恶意样本
  3. ACT: 头认证 → 内容/URL → 附件沙箱 → 租户控制面建议

适用场景

  • 钓鱼邮件拆解与 IOC
  • SPF/DKIM/DMARC 配置评估
  • BEC 商务邮件欺诈模式
  • OAuth 应用钓鱼 / 邮箱令牌滥用(联合 llm/cloud 身份)
  • 安全意识演练设计(授权)

工作流

□ 完整原始头:Received 链、From/Return-Path 一致性
□ SPF/DKIM/DMARC 对齐结果
□ URL 沙箱与附件静态(联合 malware-analysis)
□ 仿冒品牌与回复地址差异
□ 租户:反钓鱼策略、外部标记、MFA、OAuth app 同意

工具链

工具 用途
邮件客户端「查看源」
dig/nslookup SPF/DMARC 记录
urlscan / 沙箱 链接与附件
租户管理中心 策略

参考

  • references/email-auth-checklist.md
  • ../malware-analysis/ ../attack-chain/(钓鱼阶段) ../windows-ad/(令牌)

路由上下文

上游: MASTER R36
MUST NOT: 未授权对第三方域群发测试钓鱼

任务完成自检

  • 头认证结论是否完整?
  • IOC 是否可检测化(联合 threat-hunting)?
  • Checklist?
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. 3d ago First seen · 55 lines · 35 tokens per session scan A fb8815157759

Subscribe to this mod's changes

email-security is a skill published in the GitHub repository Asaiuta/reverse-workbench-skill (2 stars, last pushed 20d ago), licensed MIT. It adds 35 tokens to every session and 470 once invoked, about $0.0002 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 2026-08-31.