Discovering sub-domains

Sub-domains are used to both organize and develop a hierarchical structure for domain names, such as dividing a parent domain into smaller parts that can be easily managed by IT professionals. Furthermore, sub-domains are easily created by adding a prefix value to an existing parent domain. For instance, Google owns the google.com domain and created mail.google.com as a sub-domain that points to its online email platform. This means that sub-domains can have their own IP address, content, and hosting server, and can be managed separately from the parent domain.

As an ethical hacker, it’s important to discover sub-domains of a target as they can provide valuable information during your reconnaissance phase. They can help you identify additional systems and network infrastructure and determine the security posture of the target. In addition, you can expand the attack surface, discovering security vulnerabilities that can lead to compromising the target...