Subdomain Redirect Tracing
In cybersecurity, subdomain redirect tracing is the specialized process of following the path of a subdomain's redirection to its final destination URL. This is not just about seeing where a subdomain points, but understanding the entire chain of redirects to uncover potential security risks.
The purpose of this investigation is to:
Uncover Malicious Redirects: Trace a subdomain like login.company.com to see if it redirects to a phishing site designed to steal user credentials.
Identify Subdomain Takeovers: Follow a redirect from a subdomain to an unexpected, unmaintained third-party service, which an attacker could take over to serve their content.
Analyze Redirection Chains: Determine if a subdomain is redirecting through a series of intermediaries, which could be a sign of a malicious campaign or a misconfigured asset.
Assess Security: Examine the security of the entire redirect path, including the use of secure protocols (HTTPS) and appropriate security headers.
Subdomain redirect tracing is a critical aspect of external attack surface management, as it helps security professionals map out and understand all the public-facing assets of an organization and how they might be compromised or abused.
ThreatNG helps with subdomain redirect tracing by providing a comprehensive, external-facing view of an organization's digital presence to find and analyze redirect paths that could pose a risk.
ThreatNG's Role in Discovering and Assessing Redirects
ThreatNG's External Discovery capability performs unauthenticated discovery to find an organization's digital assets, including subdomains. This is crucial for identifying all subdomains, even those that are not publicly linked, but which may be redirecting traffic.
The platform's External Assessment feature includes specific modules to evaluate redirection risks. The External Threat Alignment capability helps uncover how an adversary might achieve initial access and establish persistence. For example, ThreatNG can detect if a subdomain like login.examplecorp.com has a redirect that bypasses a firewall or other security controls, creating an opportunity for an attacker. The Subdomain Takeover Susceptibility assessment incorporates Domain Intelligence to evaluate a website's susceptibility to subdomain takeover. This includes an analysis of DNS records and SSL certificate statuses. For instance, if an old subdomain, blog.examplecorp.com, is redirecting to an unmaintained third-party service, ThreatNG can detect that vulnerability, which an attacker could exploit to take over the subdomain and redirect users to a malicious site.
Using ThreatNG's Investigation Modules to Mitigate Risks
ThreatNG's Investigation Modules provide the tools to analyze the redirects and their sources in detail.
Subdomain Intelligence is a key module that offers detailed analysis of a subdomain's HTTP responses and headers to uncover redirects. The Content Identification feature within this module looks explicitly for "Potential Redirects". This allows security teams to verify that a redirect is secure and intentional, such as support.examplecorp.com redirecting to an expected help desk portal, and not to an unexpected or malicious URL.
Archived Web Pages can find archived versions of an organization's online presence, which may contain "Potential Redirects". This is useful for uncovering old subdomains that might be redirecting to a malicious or outdated page, which poses a security risk.
Ongoing Monitoring, Reporting, and Intelligence Repositories
Continuous Monitoring is a core capability that constantly checks an organization's external attack surface for new or changing subdomain redirects. This ensures that any new redirection risks are immediately flagged for investigation.
ThreatNG's Reporting capabilities provide a clear, prioritized view of the risks found. A report can highlight a risky subdomain redirect and provide a risk level to help you prioritize your security efforts and allocate resources effectively.
The Intelligence Repositories (DarCache) also provide valuable context. The Vulnerabilities repository provides a holistic approach to managing external risks by detailing their real-world exploitability. For example, if a subdomain is redirecting insecurely due to a known vulnerability, ThreatNG can provide details on the vulnerability and its potential impact.
Synergies with Complementary Solutions
ThreatNG's capabilities can work with complementary solutions to provide a more comprehensive security posture. 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.
