analyzing-email-headers-for-phishing-investigation

Parse email headers and DNS records to trace phishing origins.

Updated Apr 23, 2026
One-click install
npx skills add https://github.com/YukiIto1999/ctf-sleuth --skill analyzing-email-headers-for-phishing-investigation
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: analyzing-email-headers-for-phishing-investigation
Source: https://github.com/YukiIto1999/ctf-sleuth/tree/main/.claude/skills/analyzing-email-headers-for-phishing-investigation
Command: npx skills add https://github.com/YukiIto1999/ctf-sleuth --skill analyzing-email-headers-for-phishing-investigation

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill includes scripts (resource) and references (resource) components.

What problem does it solve?

Phishing emails often spoof senders and obfuscate delivery paths; this skill provides automated header analysis to trace origin, verify authenticity, and identify spoofing indicators.

Core Features & Use Cases

  • Parse email headers to extract key fields (From, To, Date, Message-ID, Return-Path, Received chain).
  • Validate SPF/DKIM/DMARC results using Authentication-Results headers and DNS lookups.
  • Map delivery path via Received headers (bottom-up) to identify hops and relays.
  • Detect header anomalies such as From/Reply-To mismatch, URL display/href mismatches, and suspicious attachments.
  • Extract URLs and attachments for further analysis and reputation checks.

Quick Start

Analyze a raw email file (EML) to produce a header analysis report and phishing indicators.

Frequently Asked Questions about analyzing-email-headers-for-phishing-investigation

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I analyze email headers to trace a phishing email's origin?

To analyze email headers for phishing investigation, parse raw EML files to extract Received chains, validate SPF, DKIM, and DMARC records, and map the delivery path bottom-up to identify the sending server's origin.

What do SPF, DKIM, and DMARC authentication results indicate in a suspicious email?

SPF, DKIM, and DMARC authentication results validate sender authenticity by checking DNS records against the email's origin. Failures or mismatches in these headers indicate sender spoofing, a common indicator in phishing investigations.

How can I detect header anomalies like From and Reply-To mismatches?

Detecting header anomalies involves parsing the email to compare the From and Reply-To fields, identify URL display and href mismatches, and flag suspicious attachments, revealing spoofing indicators used in phishing attacks.

Can I use Python to parse EML files and extract phishing indicators automatically?

Yes, you can use Python's email parsing capabilities combined with DNS and reputation lookups to automatically extract headers, validate authentication results, and detect phishing indicators from EML files.

What is the best way to map the delivery path of a spoofed email using Received headers?

Mapping the delivery path of a spoofed email requires reading the Received headers sequentially from bottom to top, identifying each network hop and relay to trace the message back to its true originating server.

What limitations exist when tracing phishing origins through email header analysis?

Tracing phishing origins via email header analysis is limited by compromised legitimate relays, forged Received headers, and the need for external DNS and reputation lookups to verify the extracted sender and URL data.