DNS Wildcard & Subdomain Takeover Inspector
Inspect DNS wildcard synthesis (*.yourdomain.com). Probe randomized hostnames in real time, analyze wildcard response synthesis, and audit dangling CNAME exposure to third-party cloud services.
Frequently Asked Questions
What is a DNS wildcard record and why do organizations deploy them?
A DNS wildcard record uses an asterisk label (*.example.com) to match any requested subdomain that does not have an explicit resource record. Organizations deploy wildcards to easily route dynamic user profile pages (user.app.com) or ensure customer typos land on a unified web portal.
How do wildcard records create security risks and blind spots?
Wildcard records mask shadow IT infrastructure by answering DNS queries for deleted or decommissioned servers. Furthermore, they interfere with reconnaissance defense by making it difficult for internal security teams to distinguish between legitimately deployed microservices and arbitrary non-existent hostnames.
What is a dangling CNAME subdomain takeover?
A subdomain takeover occurs when a DNS CNAME record points to an external cloud or SaaS hosting service (e.g. sub.example.com CNAME custom.github.io or an AWS S3 bucket) that has been deleted or released in the cloud provider. An attacker can register that abandoned resource name at the cloud provider and take complete control over your subdomain.
How does this tool test for active wildcard synthesis in real time?
The tool generates multiple cryptographically randomized subdomains (e.g. wildcard-probe-7x9q2m.yourdomain.com). Because these randomized strings definitely do not exist as explicit records, if the authoritative nameserver returns an A, AAAA, or CNAME answer instead of NXDOMAIN, wildcard synthesis is confirmed.