novaestellar/novahaku · testing/email-domain-security/SKILL.md

email-domain-security skillA

email-domain-security is agent-read markdown (skill) from novaestellar/novahaku: Rigorous, defensible email-spoofability verdict and SPF supply-chain risk analysis computed from published DNS alone. Deepens the record-level SPF/DMARC/DKIM/BIMI/MTA-STS/DNSSEC fetch recipes in the offensive-osint arsenal (§16.14) with the reasoning that section doesn't do: a priority-ordered composite verdict for whether an attacker can actually land header-From-spoofed mail in an inbox, and by which vector (exact-domain vs subdomain) — grounded in the single most-misunderstood distinction in .

Indexed from public GitHub and served as immutable, content-addressed versions. Install it pinned to an exact SHA-256 with the mdr CLI, and every file is verified against the hash recorded here before it reaches your agent. The deterministic audit below grades the latest version, and the same file always earns the same grade.

How to install

Latest version
mdr add novaestellar/novahaku/email-domain-security@v1
Exact content
mdr add novaestellar/novahaku/email-domain-security@sha256:47dfa12c7dff9999

Pin to a label to follow the author's releases, or to a sha256 to freeze the exact bytes forever. Either way the resolved hash is written to mdr.lock, and mdr install reproduces it on any machine.

Badge

mdr badge

[![mdr](https://markdownregistry.com/badge/art_xyblfxtlevnczx53.svg)](https://markdownregistry.com/a/art_xyblfxtlevnczx53)

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Versions

versioncommittedcommitsizeaudit
v1 latest2026-09-08 78e1d6b 47,075 BA view

Audit of the latest version

A  17 of 17 checks passed. Deterministic, no model, same answer every run.
  • pass: Frontmatter block present
  • pass: Frontmatter declares a name
  • pass: Frontmatter declares a description
  • pass: Size between 200 bytes and 200 KB (47075 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

GitHub

novaestellar/novahaku · 19 stars · license none · pushed 2026-09-10 · branch main

API

GET https://markdownregistry.com/api/v1/artifacts/art_xyblfxtlevnczx53
GET https://markdownregistry.com/api/v1/resolve?ref=novaestellar/novahaku/email-domain-security
GET https://markdownregistry.com/api/v1/blob/47dfa12c7dff999930789222a6efc7bfbcf01a4adc66210892fadb50582e47ba