Email Security

---
name: email-security
description: "Authorized email security review: phishing analysis, SPF/DKIM/DMARC header authentication, BEC pattern investigation, and mailbox token abuse research."
risk: offensive
source: "https://github.com/zhaoxuya520/reverse-skill"
source_repo: "zhaoxuya520/reverse-skill"
source_type: community
date_added: "2026-08-25"
license: "MIT"
license_source: "https://github.com/zhaoxuya520/reverse-skill/blob/main/LICENSE"
---
> **⚠️ AUTHORIZED USE ONLY**
> This skill is for educational purposes or authorized security assessments only.
> You must have explicit, written permission from the system owner before using this tool.
> Misuse of this tool is illegal and strictly prohibited.

> **Mandatory confirmation gate**
> Before running any command that probes, exploits, changes, persists on, extracts data from, or attempts credential access against a target:
> 1. Ask the user to state the exact target URL, IP, account, or resource.
> 2. Ask the user to confirm written authorization and the permitted scope.
> 3. Show the exact command(s) and explain their expected effect.
> 4. Wait for explicit confirmation in the current conversation.
>
> Without that confirmation, remain read-only and provide defensive guidance only. Prefer a sandbox, disposable VM, or controlled lab.

# Email Security & Phishing Analysis
## When to Use

- Analyzing suspicious messages or domain spoofing exposure.
- Validating a domain's email authentication posture.


## 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

```text
□ 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」 | 头 |
| 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？

## Limitations

- Live mailbox investigation touches personal data; minimize and anonymize.
- Header analysis cannot detect compromise that leaves no mail trail.

> Adapted from [zhaoxuya520/reverse-skill](https://github.com/zhaoxuya520/reverse-skill) (MIT).