Registration data tells you who bought the name; DNS tells you who runs the service. They are frequently different parties, and conflating them is the mistake that wrecks attribution. Everything here is passive except where flagged — but note that dig aimed at the target's own nameservers lands in the target's query logs, so resolve through a public recursive resolver or passive DNS when you care about being quiet.
Who Owns This Domain is a community-contributed Claude Code skill in the forensics sub-category. It ships as a SKILL.md file that Claude Code auto-discovers under ~/.claude/skills/who-owns-this-domain/ and loads when your prompt matches the skill's trigger.
When to invoke it: Use when running a whois lookup, querying RDAP, digging A, AAAA, MX, NS, TXT, SOA or CAA records, reading SPF includes, DKIM selectors or DMARC rua addresses, finding the registrar, registrant or nameservers, doing reverse DNS, PTR, ASN or netblock lookups, or hunting historical WHOIS and passive DNS. Applies to phishing and brand-abuse takedown, domain-dispute and UDRP evidence, vendor verification before payment, and infrastructure attribution.
The Who Owns This Domain Claude Code skill is built for security engineers, penetration testers, DevSecOps practitioners, and development teams hardening codebases and infrastructure. It's part of ClaudSkills (also referred to as Claude Skills or Claude Code Skills) — the open community-curated registry of 196,000+ SKILL.md files for Anthropic's Claude Code agent and the wider Claude ecosystem (Claude API, Claude Agent SDK).
mkdir -p ~/.claude/skills/who-owns-this-domain curl -L https://claudskills.com/skills/who-owns-this-domain/SKILL.md \ -o ~/.claude/skills/who-owns-this-domain/SKILL.md
Or just download SKILL.md directly and drop it into ~/.claude/skills/who-owns-this-domain/. Claude Code auto-discovers it on next session.
Skills live at ~/.claude/skills/who-owns-this-domain/SKILL.md on macOS/Linux, or %USERPROFILE%\.claude\skills\who-owns-this-domain\SKILL.md on Windows. See the full install guide for step-by-step instructions.
Open @claudskills_bot on Telegram, tap Open Desktop App, and the desktop app installs this skill for you. Or share the bot link with a colleague — they get the same one-tap install. Learn more →
The ClaudSkills desktop app installs any skill directly into ~/.claude/skills/ with one click — no terminal required. Pro starts at $9/mo or $149 lifetime.
For the full experience including quality scoring and one-click install features for each skill — upgrade to Pro.
SKILL.md from the source repository to ~/.claude/skills/who-owns-this-domain/SKILL.md and restart Claude Code. Both flows are detailed at claudskills.com/install/.SKILL.md file that lives under ~/.claude/skills/<name>/ and tells the Claude Code CLI agent how to perform a specific task (instructions, prompts, allowed tools). Skills are auto-discovered at session start. Who Owns This Domain is one of 67,000+ skills indexed in the open ClaudSkills catalog, classified under the Security category. Learn more at /learn/what-is-a-claude-skill/.If you reference this skill in a blog post, paper, or documentation, you can cite it as:
@misc{who-owns-this-domain-2026,
author = {UseOSINT},
title = {Who Owns This Domain [Claude Code skill]},
year = {2026},
publisher = {ClaudSkills},
url = {https://claudskills.com/skills/who-owns-this-domain/}
}Grade A · scanned 2026-09-28 — free static scan against the OWASP Agentic Skills Top 10.
The scan flagged 2 of 10 categories (filesystem, network), including lower-severity patterns. Patterns shown inside code fences are weighted as examples rather than instructions — read the grading methodology for what this does and does not guarantee.
Browse all Security skills in the ClaudSkills registry, or explore these other picks from the same category:
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SKILL.md files, not affiliated with, endorsed by, or sponsored by Anthropic.