Why Forgotten Subdomains Pose a Massive Cybersecurity Risk
As organizations grow, their web presence expands. Developers create new subdomains for testing, staging, campaigns, and third-party SaaS integrations. However, once these projects end, the subdomains are often abandoned. These forgotten subdomains are ticking time bombs for siber security.
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The Threat of Subdomain Takeover
A Subdomain Takeover occurs when an attacker gains control of a legitimate subdomain that points to an external service (like AWS, GitHub Pages, or Shopify) that has been decommissioned but still has active DNS records.
How it Works:
1. You point blog.yourcompany.com to a third-party blogging platform via a CNAME record.
2. You delete the account on that blogging platform, but forget to delete the CNAME record in your DNS settings. This is called a Dangling DNS record.
3. An attacker registers on the blogging platform, claims the same name, and now controls blog.yourcompany.com.
The Impact: * Phishing attacks: Users trust your domain, making it easy for attackers to steal login credentials. * Cookie hijacking: Attackers can read session cookies shared across your top-level domain. * Brand reputation damage: Attacking code or inappropriate content displayed under your official brand domain.
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How to Protect Your Domain Portfolio
1. Delete Expired DNS Records: Ensure all decommissioned services have their DNS records deleted immediately. 2. Implement Continuous Monitoring: Use scanning engines that alert you whenever a subdomain becomes orphaned or points to an unregistered endpoint.
Mangudai helps you find and clean up all dangling records and unused subdomains automatically.
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