WHOIS
Official Documentation: https://www.kali.org/tools/whois/¶
Cheat Sheet: WHOIS Commands¶
Purpose¶
whois retrieves domain and IP registration information: registrant, registrar, registration/expiry dates, name servers, and contact info (where available).
Scenarios¶
- CTF: Find ownership hints or related domains via registration details or contact emails.
- Real world: Verify domain ownership, check for impending expiry (possible takeover risk), or gather points of contact for disclosure.
Required info to run¶
- A domain name or IP address.
- The
whois
client installed (included in Kali). - Understand that WHOIS data can be privacy-protected; use historical WHOIS or WHOIS APIs if needed.
- Command options:
whois <domain>
→ basic lookupwhois -h <server> <query>
→ query a specific WHOIS server (advanced)- For bulk lookups, use APIs (paid) to avoid rate limiting.
Example commands & outputs¶
# Domain whois
$ whois example.com
# Output snippet:
# Domain Name: EXAMPLE.COM
# Registrar: RESERVED-Internet Assigned Numbers Authority
# Creation Date: 1995-08-04T04:00:00Z
# Name Server: A.IANA-SERVERS.NET
# IP whois (shows allocation/owner)
$ whois 8.8.8.8
# Output snippet:
# NetRange: 8.0.0.0 - 8.127.255.255
# Organization: Google LLC
whois Basics
- WHOIS can be rate-limited; space queries. For many domains, contact details are redacted.
- For historical records, use services like SecurityTrails, DomainTools, or whoisxmlapi (API keys may be required).
- Combine WHOIS with DNS enumeration and
theHarvester
for fuller recon.