analyzing-email-headers-for-phishing-investigation SKILL.md skillA
analyzing-email-headers-for-phishing-investigation from 26zl/cybersec-toolkit is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add 26zl/cybersec-toolkit/analyzing-email-headers-for-phishing-investigation@v1.0Pins v1.0 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- 26zl/cybersec-toolkit
- Path
.claude/skills/analyzing-email-headers-for-phishing-investigation/SKILL.md- Versions recorded
- 2
- Latest version
- v1.0, committed May 25, 2026
- First version recorded
- Apr 30, 2026
- Size
- 11,904 bytes
- Repository stars
- 87
- License
- MIT
Parse and analyze email headers to trace the origin of phishing emails, verify sender authenticity, and identify.
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
# Analyzing Email Headers for Phishing Investigation ## When to Use - When investigating a suspected phishing email to determine its true origin - For verifying sender authenticity and detecting email spoofing - During incident response when a user has clicked a phishing link - When tracing the delivery path and relay servers of a suspicious email - For validating SPF, DKIM, and DMARC alignment to identify forgery ## Prerequisites - Raw email headers from the suspicious message (EML or MSG format) - Understanding of SMTP protocol and email header fields - Access to DNS lookup tools (dig, nslookup) for SPF/DKIM/DMARC verification - Email header analysis tools (MHA, emailheaders.net concepts) - Python with email parsing libraries for automated analysis - Access to threat intelligence platforms for IP/domain reputation ## Workflow ### Step 1: Extract Raw Email Headers ```bash # Export from Outlook: Open email > File > Properties > Internet Headers # Export from Gmail: Open email > Three dots > Show original # Export from Thunderbird: View > Message Source # If working with EML file from forensic image …
Read the whole file at its exact version.
How to install
mdr add 26zl/cybersec-toolkit/analyzing-email-headers-for-phishing-investigation@sha256:7404730b818b8758The line at the top of this page pins the label v1.0, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_rgrpi2rfbptn6ix4)
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Versions
The registry has recorded 2 versions of this file, between Apr 30, 2026 and May 25, 2026, about one every 25 days.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| v1.0 latest | 2026-05-25 | f3e3c16 | 11,904 B | A | view · diff |
| v1.0 | 2026-04-30 | 9ae5eef | 11,769 B | A | view |
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (11904 bytes)
- pass: No zero-width or bidi control characters
- pass: No instruction hidden inside an HTML comment
- pass: No link to an exfiltration or paste host
- pass: No credential-shaped string
- pass: No instruction to send local credentials anywhere
- pass: No text hidden with inline styles
- pass: No prompt-injection phrasing
- pass: No curl or wget piped into a shell
- pass: No recursive delete of root, home or parent
- pass: No instruction to read or print local credentials
- pass: No base64 blob over 200 characters
- pass: No link to a raw IP address
- pass: No script tag
Source
26zl/cybersec-toolkit · 87 stars · license MIT · pushed 2026-11-01 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_rgrpi2rfbptn6ix4 GET https://markdownregistry.com/api/v1/resolve?ref=26zl/cybersec-toolkit/analyzing-email-headers-for-phishing-investigation GET https://markdownregistry.com/api/v1/blob/7404730b818b8758244346d36508caff2f4a6b06b8c19dc286c7f9bae118ee9b
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.
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