1. Dehashed—View leaked credentials.
2. SecurityTrails—Extensive DNS data.
3. DorkSearch—Really fast Google dorking.
4. ExploitDB—Archive of various exploits.
5. ZoomEye—Gather information about targets.
6. Pulsedive—Search for threat intelligence.
7. GrayHatWarfare—Search public S3 buckets.
8. PolySwarm—Scan files and URLs for threats.
9. Fofa—Search for various threat intelligence.
10. LeakIX—Search publicly indexed information.
11. DNS Dumpster—Search for DNS records quickly.
12. Full Hunt—Search and discovery attack surfaces.
13. AlienVault—Extensive threat intelligence feed.
14. ONYPHE—Collects cyber-threat intelligence data.
15. Grep App—Search across a half million git repos.
16. URL Scan—Free service to scan and analyse websites.
17. Vulners—Search vulnerabilities in a large database.
18. Way Back Machine—View content from deleted websites.
19. Shodan—Search for devices connected to the internet.
20. Netlas—Search and monitor internet connected assets.
21. CRT sh—Search for certs that have been logged by CT.
22. Wigle—Database of wireless networks, with statistics.
23. Public WWW—Marketing and affiliate marketing research.
24. Binary Edge—Scans the internet for threat intelligence.
25. GreyNoise—Search for devices connected to the internet.
26. Hunter—Search for email addresses belonging to a website
27. Censys—Assessing attack surface for internet connected devices.
28. Intelligence X—Search Tor, I2P, data leaks, domains, and emails.
29. Packet Storm Security—Browse latest vulnerabilities and exploits.
30. Search Code—Search 75 billion lines of code from 40 million projects.