Stop domain takeovers that bypass DMARC
DNS Guardian continuously monitors your DNS to prevent SubdoMailing, dangling DNS, and CNAME takeovers.
Stop domain takeovers that bypass DMARC
DNS Guardian continuously monitors your DNS to prevent SubdoMailing, dangling DNS, and CNAME takeovers.
In February 2024, SubdoMailing sent millions of fraudulent emails by hijacking abandoned subdomains, despite DMARC being set to reject. The attack exposed DNS-level vulnerabilities that authentication protocols can’t protect against, allowing attackers to operate entirely outside traditional email defenses.
SubdoMailing showed attackers can bypass DMARC by exploiting DNS misconfigurations in subdomains. A domain can have perfect enforcement while forgotten or misconfigured subdomains are still abused.
Finding DNS vulnerabilities requires teams to constantly monitor and correlate signals across infrastructure. Without automation, these risks are extremely difficult to detect before damage occurs.
Dangling DNS records, expired CNAMEs, or unused subdomains create opportunities for domain takeover. Attackers exploit them to send convincing emails that bypass security controls.
Continuous monitoring
Runs 24/7 to catch new vulnerabilities as they appear, not just at scheduled scan intervals.
Subdomain discovery
Identifies all subdomains associated with your domain, including forgotten or shadow IT subdomains that could be exploited.
Dangling DNS detection
Finds misconfigured or unused DNS records that are susceptible to takeover—like expired CNAMEs pointing to deleted resources.
Active threat identification
Detects subdomains already controlled by attackers through CNAME takeovers, poisoned SPF records, or nameserver delegation attacks.
Risk assessment and prioritization
Analyzes the severity and business impact of identified vulnerabilities so you know what to fix first.
Actionable remediation guidance
Provides clear steps to address each identified risk and strengthen your domain security posture.
For organizations that have secured email and now need DNS visibility
DNS Guardian identifies misconfigurations, dangling records, and subdomains vulnerable to takeover before attackers can exploit them. It provides actionable insights to fix vulnerabilities and maintain DNS hygiene across your entire domain infrastructure.
Security and compliance teams
You've implemented DMARC at p=reject, but SubdoMailing showed that attackers can still exploit DNS weaknesses. DNS Guardian closes that gap, giving you complete visibility and control over all potential attack vectors.
Enterprises with complex infrastructure
Managing DNS across multiple subdomains, acquisitions, or legacy systems creates blind spots. DNS Guardian discovers and monitors everything—including forgotten subdomains that create risk.
Only available from Red Sift
DNS Guardian is made possible through Red Sift's acquisition of Hardenize. No other DMARC tool on the market offers continuous DNS monitoring at this level.
For businesses looking to protect against malicious mail that bypasses DMARC, Red Sift OnDMARC is the market leader.
See what DNS vulnerabilities exist in your infrastructure