hunt-subdomain SKILL.md skillB
hunt-subdomain from novaestellar/novahaku is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add novaestellar/novahaku/hunt-subdomain@git:20260927.e881f8aPins git:20260927.e881f8a in mdr.lock. Pin the fingerprint instead.
- Audit grade
- B, 16 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- novaestellar/novahaku
- Path
testing/hunt/hunt-subdomain/SKILL.md- Versions recorded
- 1
- Latest version
- git:20260927.e881f8a, committed Sep 27, 2026
- Size
- 25,030 bytes
- Repository stars
- 28
- License
- MIT
Hunting skill for subdomain takeover vulnerabilities. Includes modern provider fingerprints — Microsoft Azure DevOps `cloudapp.azure.com` regional-pool re-issue (1-click OAuth ATO via wildcard `reply_to`, Binary Security), Zendesk help-desk takeover → email interception → password reset chain (0xprial writeup), Vercel `cname.vercel-dns.com` deleted-project takeover, plus general Fastly CDN service re-attach and S3 dangling-bucket cookie-scope techniques. Use when hunting subdomain takeover —…
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
## Crown Jewel Targets Subdomain takeover is high-value because it allows an attacker to serve content from a **trusted, company-owned domain** — bypassing browser same-origin trust, phishing filters, and user skepticism simultaneously. **Highest payout contexts:** - Subdomains of major SaaS brands (Shopify, Snapchat, Mozilla, Yelp) where the trusted domain has user session context - CDN-backed subdomains (Fastly, CloudFront) where CNAME points to unclaimed origins - Third-party service integrations: UserVoice, WordPress.com, GitHub Pages, GitLab Pages, Heroku, Zendesk - Preview/staging/dev subdomains (`new.`, `preview.`, `course.`, `delivery.`, `addons-preview.`) — abandoned after feature launches - Subdomains used for OAuth redirect URIs or SSO endpoints — these pay highest **Asset types that matter most:** - CNAME records pointing to deprovisioned third-party services - NS delegations to abandoned zones - A records pointing to unallocated cloud IPs (less common) - GitLab/GitHub Pages with unclaimed project namespaces --- ## Attack Surface Signals **DNS signals:** …
Read the whole file at its exact version.
How to install
mdr add novaestellar/novahaku/hunt-subdomain@sha256:aac68521ad4a90faThe line at the top of this page pins the label git:20260927.e881f8a, 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_qbon3f74o3imbna7)
1 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 1 version of this file, committed on Sep 27, 2026.
Audit of the latest version
- fail: No script tag (matched: <script)
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (25030 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
Starting a new one? Use a template for SKILL.md on mdpantry, which passes every one of these checks and says what to change in it.
Source
novaestellar/novahaku · 28 stars · license MIT · pushed 2026-09-28 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_qbon3f74o3imbna7 GET https://markdownregistry.com/api/v1/resolve?ref=novaestellar/novahaku/hunt-subdomain GET https://markdownregistry.com/api/v1/blob/aac68521ad4a90fa5a21777f2c1c3ac05a1dfc080e066e88b0ce42571f174ca3
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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