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domain-intel

Identify subdomains, SSL certificates, WHOIS data, DNS records, and domain availability.

Updated Apr 12, 2026
Search Tags:#dns#ssl#osint#whois#subdomain-discovery#domain-intel#passive-recon
One-click install
npx skills add https://github.com/thisismynewfmail-ui/Monika-agent --skill domain-intel-thisismynewfmail-ui
Or copy as Structured Prompt for Agent▼
Please help me install this Agent Skill.
Skill: domain-intel
Source: https://github.com/thisismynewfmail-ui/Monika-agent/tree/main/optional-skills/research/domain-intel
Command: npx skills add https://github.com/thisismynewfmail-ui/Monika-agent --skill domain-intel-thisismynewfmail-ui

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill includes scripts (resource) components.

What problem does it solve?

It provides automated, passive intelligence about domains—subdomains, SSL certificates, WHOIS records, DNS details, and availability—without requiring any external libraries or API keys.

Core Features & Use Cases

  • Subdomain Discovery: Retrieves subdomains from Certificate Transparency logs (crt.sh).
  • SSL Inspection: Checks certificate details, expiration dates, and cipher suites.
  • WHOIS Lookup: Extracts registrar, creation, and expiration information.
  • DNS Records: Resolves A, AAAA, MX, NS, TXT, and CNAME records using system DNS and Google DoH.
  • Availability Check: Determines if a domain is likely registered or available using passive signals.
  • Bulk Analysis: Executes multiple checks across many domains in parallel. Use case: A security analyst can quickly audit a list of competitor domains to map their infrastructure and monitor changes.

Quick Start

Ask the skill to list subdomains for example.com.

Frequently Asked Questions about domain-intel

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I find subdomains and SSL certificate history without using external APIs?▼

Passive domain reconnaissance gathers DNS records, WHOIS data, and subdomains from public sources without querying the target directly. It leverages Certificate Transparency logs and DNS over HTTPS to map infrastructure while remaining undetected by the target network.

Can I perform bulk WHOIS and DNS lookups across multiple domains without installing dependencies?▼

Yes, bulk WHOIS and DNS lookups across multiple domains can be executed in parallel without dependencies. The tool runs simultaneous checks using only the Python standard library and public passive data sources, requiring no additional installations.

What DNS record types can I resolve using passive reconnaissance with the Python standard library?▼

You can resolve A, AAAA, MX, NS, TXT, and CNAME DNS record types using passive reconnaissance. Resolutions are performed using system DNS and Google DNS over HTTPS without requiring external API keys or additional Python packages.

Does passive OSINT domain intelligence work for checking if a domain is available or registered?▼

Yes, passive OSINT domain intelligence works for checking domain availability by evaluating passive signals. It determines if a domain is likely registered or available without sending direct queries to the target domain's servers.

What are the limitations of using passive recon for security assessments instead of active scanning?▼

Passive recon limitations include reliance on historical data from Certificate Transparency logs and third-party DNS caches, which may not reflect real-time infrastructure changes or discover unindexed internal subdomains like active scanning would.

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