Subdomain Takeover Scanner
A Subdomain Takeover Scanner is a cybersecurity tool or technology designed to detect and identify subdomains that are vulnerable to takeover automatically.
To understand this, let's break down the key components:
Subdomain: A subdomain is an extension of a main domain name. For example, in "blog.example.com," "blog" is the subdomain, and "example.com" is the main domain. Organizations use subdomains to organize different website sections or host various services.
Subdomain Takeover: This type of cyberattack occurs when an attacker gains control of a subdomain that is no longer in use by the organization. This often happens when a subdomain points to an external service (like a cloud hosting platform or a content delivery network). Still, the organization has stopped using that service without adequately removing the DNS record. Attackers can then claim that service and effectively "take over" the subdomain.
Here's how a Subdomain Takeover Scanner works and its importance:
Detection: The scanner automates checking numerous subdomains for potential takeover vulnerabilities. It typically does this by:
Enumerating Subdomains: Discovering a list of subdomains associated with a target domain.
Checking DNS Records: Examining the DNS records of each subdomain to see where it points.
Verifying Service Availability: Attempting to access the services associated with those DNS records to see if they are active and properly configured.
Identification: The scanner identifies subdomains with discrepancies between the DNS record and the service. For example, if a DNS record points to a cloud service that no longer exists or is not configured correctly by the organization, the scanner flags it as a potential takeover vulnerability.
Importance: Subdomain takeover scanners are essential because they help organizations proactively identify and remediate subdomain takeover vulnerabilities before attackers can exploit them. Subdomain takeovers can have serious consequences, including:
Website Defacement: Attackers can host malicious content on the compromised subdomain.
Phishing Attacks: Attackers can use the subdomain to host phishing pages to steal user credentials.
Data Theft: If the subdomain was previously used to host sensitive data, attackers might be able to regain access.
Brand Damage: A subdomain takeover can damage an organization's reputation and erode trust.
ThreatNG's capabilities can significantly enhance the effectiveness of subdomain takeover detection:
ThreatNG excels at external discovery, which is the foundation for identifying potential subdomains vulnerable to takeover.
It can perform purely external unauthenticated discovery using no connectors.
ThreatNG provides a complete list of potential targets for a subdomain takeover scanner by comprehensively mapping an organization's attack surface, including all subdomains.
This broad discovery is crucial because a subdomain takeover scanner can only check known subdomains.
ThreatNG's external assessment features directly contribute to identifying subdomain takeover vulnerabilities:
Subdomain Takeover Susceptibility: ThreatNG has a specific assessment rating for "Subdomain Takeover Susceptibility."
To evaluate a website's susceptibility to subdomain takeover, the ThreatNG Security Rating uses external attack surface and digital risk intelligence that incorporates Domain Intelligence.
This intelligence includes a comprehensive analysis of the website's subdomains, DNS records, SSL certificate statuses, and other relevant factors.
This assessment provides a focused analysis of the key indicators of a potential subdomain takeover vulnerability.
3. Reporting
ThreatNG's reporting capabilities deliver valuable information regarding subdomain takeover risks.
Security ratings and prioritized reports can highlight subdomains with high takeover susceptibility, enabling security teams to focus on the most critical issues.
ThreatNG's continuous monitoring of the external attack surface is essential for detecting changes that could lead to subdomain takeover vulnerabilities.
Changes in DNS records, SSL certificate statuses, or the availability of associated services can all indicate an increased risk of subdomain takeover.
By continuously monitoring these factors, ThreatNG provides timely alerts and allows for proactive mitigation.
ThreatNG's investigation modules offer detailed insights for analyzing potential subdomain takeover vulnerabilities:
Domain Intelligence: ThreatNG's Domain Intelligence module provides in-depth information about an organization's domain infrastructure, including subdomains, DNS records, and related configurations.
This detailed information is crucial for confirming and understanding subdomain takeover vulnerabilities.
ThreatNG's intelligence repositories provide context that can be useful in assessing the risk associated with potential subdomain takeovers.
For example, information on known vulnerabilities or misconfigurations can help security teams understand the potential impact of a successful subdomain takeover.
7. Working with Complementary Solutions
ThreatNG can work with other security solutions to improve subdomain takeover management:
Vulnerability Management Tools: ThreatNG's identification of subdomain takeover vulnerabilities can be integrated into vulnerability management tools for tracking and remediation.
Security Information and Event Management (SIEM) Systems: ThreatNG's monitoring data and alerts related to subdomain takeover risks can be fed into SIEM systems to correlate with other security events and improve threat detection.
