Subdomain Redirection Risk
In cybersecurity, a subdomain redirection risk exists when a subdomain is configured to forward users to another URL in a way that can be exploited for malicious purposes. These risks stem from the potential for unintended or harmful outcomes of what is often a legitimate technical process.
The primary dangers associated with subdomain redirection risks include:
Phishing and Malware Distribution: An attacker can use a subdomain that appears legitimate, such as login.trustedbank.com, to redirect users to a fraudulent website designed to steal their credentials or infect their device with malware. This deception is effective because the initial URL looks safe to the user.
Subdomain Takeover: If a subdomain is redirecting to an external service that is no longer in use, an attacker can register that service and take control of the subdomain. This allows the attacker to use the legitimate-looking subdomain for their own purposes, such as hosting malicious content, which can damage the brand's reputation and security.
Exposure of Outdated Content: A subdomain might be redirecting to an old, unmaintained version of a website or application. This older content may contain outdated security headers, unpatched software, or exposed data, creating a security hole that an attacker can use to pivot to other parts of the network.
SEO and Brand Hijacking: Malicious redirects can be used to divert web traffic and search engine authority to a competitor's site or to a site selling counterfeit products. This can result in a loss of revenue and significant brand damage.
Ultimately, these risks exist because subdomain redirects can be hard to track and monitor, especially for organizations with a large number of digital assets. Without proper oversight, a simple redirection can become a severe security liability.
ThreatNG helps mitigate subdomain redirection risks by proactively identifying and analyzing these risks from an external, attacker's perspective. It provides continuous visibility and detailed context to help organizations manage these often-overlooked vulnerabilities.
External Discovery and Assessment
ThreatNG's External Discovery capability performs unauthenticated discovery to find an organization's digital assets, including subdomains, without needing any internal access. This is crucial for identifying subdomains that may have been forgotten or are not publicly linked, but which still exist and could be redirecting traffic.
The platform's External Assessment feature includes specific modules to evaluate redirection risks. The Subdomain Takeover Susceptibility assessment is particularly relevant as it uses Domain Intelligence to analyze subdomains, DNS records, and SSL certificates to identify if a subdomain is vulnerable to being hijacked. For example, if a subdomain like oldblog.examplecorp.com is pointing to an external service that has been discontinued, ThreatNG would flag this as a potential takeover risk, which an attacker could exploit to host a malicious redirect.
Investigation, Reporting, and Monitoring
ThreatNG’s Investigation Modules provide the tools to delve deeper into redirection risks. The Subdomain Intelligence module allows for detailed analysis of a subdomain's HTTP responses and headers to determine if it is redirecting. The Content Identification feature within this module can also specifically find "Potential Redirects". This allows security teams to verify that a redirect is secure and intentional, such as support.examplecorp.com redirecting to helpdesk.zende.sk/examplecorp, and not to an unexpected or malicious URL.
ThreatNG provides Continuous Monitoring of the external attack surface to detect any new or changing subdomain redirects immediately. This is essential for catching new redirection risks as soon as they appear. The platform's Reporting capabilities, including technical and prioritized reports, help organizations manage and act on these findings by providing risk levels and recommendations.
Intelligence Repositories and Synergies with Other Solutions
ThreatNG’s Intelligence Repositories, branded as DarCache, provide valuable context for redirection risks. For instance, the Vulnerabilities (DarCache Vulnerability) repository offers a holistic approach to managing external risks by detailing the real-world exploitability of a vulnerability. If a subdomain is redirecting in an insecure manner due to an unpatched vulnerability, ThreatNG can provide context on its potential for exploitation.
ThreatNG can work with complementary solutions to enhance an organization's defense against redirection risks. For example, if ThreatNG identifies a subdomain redirecting to a known phishing site, it could communicate this finding to a threat intelligence platform (TIP) to automatically update blocklists and protect users from accessing the malicious URL. Additionally, a Security Orchestration, Automation, and Response (SOAR) platform could use ThreatNG's findings to automatically trigger a playbook to send an alert to the security team and open a case for further investigation or domain takedown.
