find-hidden-subdomains
From the author
Enumerate an organisation's subdomains and sibling domains from Certificate Transparency logs and passive DNS, without sending traffic to the target. Covers crt.sh and CT log queries, certificate SAN fields, subfinder and amass, and newly issued TLS certificates. Use when looking for staging, dev, admin or VPN hosts, mapping the full hostname footprint of a domain, or spotting infrastructure a company forgot it had. Applies to attack-surface mapping, vendor and supply-chain security review, brand-infringement discovery, and M&A technical diligence. Reference at useosint.com/skills/find-hidden-subdomains.
Install
npx skills add UseOSINT/Skills --skill find-hidden-subdomains -a claude-code
Installs to .claude/skills/find-hidden-subdomains/ · Each command fetches the skill straight from GitHub with the open skills CLI.
Byte-identical to the scanned commit, with the repository’s licence and a SOURCE.txt.
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Why 80
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