analyzing-email-headers-for-phishing-investigation

analyzing-email-headers-for-phishing-investigation is a skill for Claude Code, Codex from andycungkrinx91/konoha. It costs 44 tokens per session (3,262 once invoked), scanned A, a copy of analyzing-email-headers-for-phishing-investigation, MIT.

A procedure for examining the hidden routing and authentication information in an email to investigate phishing. It covers sender checks such as SPF, DKIM, and DMARC, which are email-domain rules used to detect forged messages.

In plain words
What is it for?
Use it to inspect raw EML or MSG headers, check DNS-based sender records, identify spoofing, and trace delivery paths.
Why use it?
It helps distinguish a genuine sender from a forged one and trace the servers that handled a suspicious message. This supports phishing investigations and incident response.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: installed under .agents/ (shared by several agents).

Good fit Use it to inspect raw EML or MSG headers, check DNS-based sender records, identify spoofing, and trace delivery paths.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/andycungkrinx91/konoha/analyzing-email-headers-for-phishing-investigation
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.

Any agent
npx skills add andycungkrinx91/konoha --skill analyzing-email-headers-for-phishing-investigation
Clone the repo
git clone --depth 1 https://github.com/andycungkrinx91/konoha

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 analyzing-email-headers-for-phishing-investigation

README.md
[![agentmods](https://agentmods.dev/badge/skills/andycungkrinx91/konoha/analyzing-email-headers-for-phishing-investigation/github.svg)](https://agentmods.dev/skills/andycungkrinx91/konoha/analyzing-email-headers-for-phishing-investigation)
Your own site
<a href="https://agentmods.dev/skills/andycungkrinx91/konoha/analyzing-email-headers-for-phishing-investigation"><img src="https://agentmods.dev/badge/skills/andycungkrinx91/konoha/analyzing-email-headers-for-phishing-investigation/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 analyzing-email-headers-for-phishing-investigation

Your own site · 80×15
<a href="https://agentmods.dev/skills/andycungkrinx91/konoha/analyzing-email-headers-for-phishing-investigation"><img src="https://agentmods.dev/badge/skills/andycungkrinx91/konoha/analyzing-email-headers-for-phishing-investigation.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 44 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,262 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. A grade says what 26 rules found in the file — not that it is safe.
Origin 86% copy Near-identical to another mod 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 $0.00044 $0.03262
Opus 5.5 $0.00018 $0.01305
Sonnet 5.5 $0.00009 $0.00652
Haiku 4.5 $0.00004 $0.00326

Measured today against content hash 755f45233a32, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

analyzing-email-headers-for-phishing-investigation scanned grade A with 1 finding 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 today.

The scan reads SKILL.md. This mod also ships 1 executable file (scripts/agent.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

curl -s "https://api.abuseipdb.com/api/v2/check?ipAddress=${SENDING_IP}" \
Origin

This is a copy

86% identical to analyzing-email-headers-for-phishing-investigation — 8 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

.agents/skills/akatsuki-skill/references/anthropic-cybersecurity-skills-assets/skills/analyzing-email-headers-for-phishing-investigation/SKILL.md · 364 lines

How it starts

The opening of the file, as written. The whole thing — 364 lines — stays where its author put it; the contents beside it link to each section on GitHub.

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

# 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
cp /mnt/evidence/Users/suspect/AppData/Local/Microsoft/Outlook/phishing_email.eml \
   /cases/case-2024-001/email/

# If working with PST file, extract individual messages
pip install pypff
python3 << 'PYEOF'
import pypff

pst = pypff.file()
pst.open("/cases/case-2024-001/email/outlook.pst")
root = pst.get_root_folder()

def extract_messages(folder, path=""):
    for i in range(folder.get_number_of_sub_messages()):
        msg = folder.get_sub_message(i)
        headers = msg.get_transport_headers()
        subject = msg.get_subject()
        if headers:
            filename = f"/cases/case-2024-001/email/msg_{i}_{subject[:30]}.txt"
            with open(filename, 'w') as f:
                f.write(headers)
    for i in range(folder.get_number_of_sub_folders()):
        extract_messages(folder.get_sub_folder(i))

extract_messages(root)
PYEOF

Step 2: Parse the Email Header Chain

Read the full file on GitHub · 364 lines

Files

What ships with it

2 files 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. today First seen · 364 lines · 44 tokens per session scan A 755f45233a32

Subscribe to this mod's changes

analyzing-email-headers-for-phishing-investigation is a skill published in the GitHub repository andycungkrinx91/konoha (12 stars, last pushed today), licensed MIT. It adds 44 tokens to every session and 3,262 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 1 finding (makes network calls). It is 86% identical to analyzing-email-headers-for-phishing-investigation, differing in 8 lines, and is treated as a copy.

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