Subdomain Scan (2024)

FAQs

What is subdomain scanning? ›

Subdomain scanning is a process of identifying subdomains for a given domain. This can be useful for a number of reasons, such as identifying subdomains that may be vulnerable to attack or finding subdomains that contain sensitive information.

A Subdomain Finder is a subdomain enumeration tool that helps you discover subdomain hosts (aka subdomain FQDNs) which serve specific functions for your target (e.g. hosting public websites, private subdomains for testing web apps, URLs where you can find backups, etc.).

It's a cyber threat executed when an attacker gains control of a legitimate subdomain that's no longer in use, then cleverly exploits the forgotten or misconfigured dangling DNS to host their own content on the previously used zone.

A subdomain is, as the name would suggest, an additional section of your main domain name. You create subdomains to help organize and navigate to different sections of your main website. Within your main domain, you can have as many subdomains as necessary to get to all of the different pages of your website.

In the Domain Name System (DNS) hierarchy, a subdomain is a domain that is a part of another (main) domain. For example, if a domain offered an online store as part of their website example.com , it might use the subdomain shop.example.com .

The domain is the highest level in the website address hierarchy. Subdomains are secondary domains that are part of the primary domain. For instance, in "blog.example.com," "blog" is the subdomain of the "example.com" domain. Subdomains allow you to divide sections of a website under the umbrella of the main domain.

Regular domains are your standard URLs like splashthat.com or splashthat. events. Subdomains are a unique URL that lives on your purchased domain as an extension in front of your regular domain like support.splashthat.com or blockparty.splashthat.com.

EasyDMARC's Domain Scanner is a free, powerful, easy-to-use online tool that allows you to check the health and security of your domain in one click. Simply enter your domain name and scan it.

Is subdomain takeover illegal? ›

Subdomain takeover can have severe legal implications, as attackers may engage in illegal activities or host malicious content on compromised subdomains. It's crucial to report any such incidents to law enforcement authorities and take immediate steps to mitigate the risks to protect your reputation and users.

Attackers can impersonate legitimate domain names by creating similar domain names or subdomains that look similar to the real ones. For example, an attacker could create a fake domain name “gooogle.com” with three “o's” instead of two, making it difficult for the victim to distinguish it from the real Google website.

The Subdomain Scanner uses the target domain's DNS server (or any other DNS server specified) to scan the DNS records for possible subdomains. While scanning, the Subdomain Scanner will also automatically identify if the domain being scanned uses wildcards (*. example.com).

subfinder is a subdomain enumeration tool written in the Go programming language. Subfinder is used for discovering passive subdomains of websites by using digital sources like Censys, Chaos, Recon. dev, Shodan, Spyse, Virustotal, and many other passive online sources.

However, Google treats subdomains as separate sites.

While “blog.example.com” and “example.com” may share a root domain, Googlebot will view them as distinct domains and crawl and index them accordingly.

Termed “SubdoMailing” by Guardio, this series of attacks exploits the compromised subdomains of reputable companies to disseminate malicious emails. Investigations have revealed that this malicious campaign has been active since 2022.

Subdomains aren't directly bad for SEO, but they're not always the most strategic choice.

Subdomains are used to segregate and organize different sections of a website for better navigation and content management. Here are some examples: blog.websitename.com: Focuses on the blog, distinct from the main site.