Map the public attack surface of any domain: discover subdomains, hosts, IP addresses and emails from free public OSINT sources (crt.sh, Certspotter, HackerTarget, DuckDuckGo). Powered by theHarvester. No setup, no API keys — for recon, bug-bounty and due diligence.

Discover subdomains of any domain fast using the open-source Subfinder engine — passive enumeration from dozens of public sources (certificate transparency, DNS datasets, search engines). For attack-surface mapping and authorized security research.

Subdomain Finder & Recon Tool

andok/subdomain-finder

Discover subdomains for any target via passive OSINT sources. Ideal for security bug bounties and attack surface mapping.

Subdomain Finder - CT Log Enumeration + Live DNS Check

eliai/subdomain-finder

Enumerate a domain's subdomains from Certificate Transparency logs, with an optional live DNS resolve. All subdomains in one record. $0.005 per domain (not per subdomain), far cheaper than paid finders; failures are free.

Automated reconnaissance actor for bug bounty hunters

wonderful_beluga/automated-reconnaissance-actor-for-bug-bounty-hunters

This Apify actor automates bug bounty recon by scraping the Wayback Machine and GitHub for legacy attack surfaces. It extracts historical URLs, public code, and deprecated files, parsing them to uncover hidden subdomains and forgotten API endpoints. The findings are saved into structured JSON files.

Subdomain Finder - Discover Subdomains via CT Logs

logiover/subdomain-finder

Discover every subdomain of any domain using Certificate Transparency logs (crt.sh). Fast bulk subdomain enumeration for security recon, attack-surface mapping, asset discovery and SEO. No API key — export to CSV or JSON.

Domain OSINT Recon

prooflio/domain-osint-recon

Aggregates WHOIS, DNS records, certificate-transparency subdomains and PTR records for a domain into one structured report.

Subdomains Finder API - Realtime DNS Subdomain Scanner

dev00/subdomains-finder-api-realtime-dns-subdomain-scanner

High-performance subdomain scanner that retrieves all registered subdomains, IP addresses, and Cloudflare protection status for any given domain.

Find exposed admin panels, missing/weak security headers, sensitive file leaks, and HTTPS misconfigurations across target domains. Export prioritised risk scores and JSON reports. Run via API, schedule scans, or integrate with bug bounty tools.

Run a full due-diligence scan on any domain in one call: WHOIS registration, DNS records, SSL certificate, subdomain discovery (crt.sh), and technology fingerprint. Built for OSINT, security recon, M&A due diligence, and lead research.