- Introduction to Whois
- Whois Flow
- What is Reverse Whois?
- Reverse Whois Flow
- 100 domains or 84615 domains?
Introduction to Whois
Whois, is used to query domain names, IP addresses, and ASN (autonomous system numbers or IP blocks) for their registered information. In simpler terms, if a user owns a domain or IP address, they have to give information like email, organization name, address, etc. to the domain registrar (like GoDaddy and Google Domains) that is stored in a database.
The above image is a snap of whois information of the domain "disney.com".
Whois - Flow
Input == Domain Name Output == Registrant Information
What is Reverse Whois?
The reverse whois tool allows you to search for domain names owned by the registrant's email address, company owner, or admin name.
The mapping in whois is one-to-one, whereas in reverse whois it is one-to-many. It allows you to increase your attack surface from one domain to multiple domains that are registered by the same organization.
Reverse Whois - Flow
Input == Registrant Information Output == Domains
100 domains or 84615 domains?
If you want to stand in the same queue as other hackers or bug bounty hunters, don't buy the pro subscriptions to these services. If you think you want to attack things that no one is attacking, you should buy subscriptions to these tools.
A general free whois query for "Disney Enterprises, Inc." will give you 100 domains whereas a paid query will give 84615 domain names.
Now think about this when you are attacking you want to hack on 100 assets of an organization or 84000+ assets?
Thank You for Reading!