Performing WHOIS Footprinting

To perform a WHOIS lookup using DomainTools — a leading web-based WHOIS intelligence platform.

Introduction

WHOIS Footprinting is one of the most fundamental and effective passive reconnaissance techniques in an attacker's toolkit. It leverages publicly available registration data to extract critical information about a target organization's domain infrastructure — all without sending a single packet to the target.

What is WHOIS?

WHOIS is a query and response protocol used to interrogate databases that store the registered users or assignees of Internet resources — including domain names, IP address blocks, and autonomous systems. it operates on TCP port 43 and exposes a wealth of organizational data to anyone who knows how to query it.

Methodology

Web-Based WHOIS via DomainTools

Step 1: Access the WHOIS Platform Open your web browser (Firefox is recommended on Kali Linux) and navigate to:

http://whois.domaintoools.com

http://whois.domaintoools.com

Step 2: Enter Your Target Domain In the search bar, enter the target domain you wish to profile. For this lab, we use TryHackMe as our test domain:

Target: www.tryhackme.com

Target: www.tryhackme.com

TIP: In real engagements, your target domain would be the organization you are authorized to test. Always obtain written authorization before profiling any domain you do not own.

Step 3: Analyze the Results Once the search completes, DomainTools will return a rich intelligence report. Systematically review and document each of the following fieldsField

Description / Example Value

Registrant Name: Legal owner of the domain — may reveal key personnel or corporate entities

Registrant Organization: The organization that registered the domain

Registrar: Platform used to register the domain (e.g., GoDaddy, Namecheap, Google Domains)

Creation Date: When the domain was first registered — useful for timeline analysis

Expiration Date: When the domain expires — potential domain hijacking window

Updated Date: Last modification — may indicate recent infrastructure changes

Name Servers: DNS servers managing the domain — reveals hosting providers and network topology

Registrant Email: Contact email — primary phishing/social engineering target

Registrant Phone: contact phone number — useful for vishing and physical recon

Registrant Address: Physical address — supports physical penetration test planning

Conclusion

Using this information an attacker can create a map of the organization's network and further mislead domain owners with social engineering and obtain internal details.

As cybersecurity professionals, understanding this technique from the attacker's perspective is essential. It informs how we advise organizations to harden their domain registrations, protect employee contact information, and build a defense-in-depth strategy that accounts for publicly available intelligence.