Skip to main content
← All controls
DE.CM-4 / PR.DS-5 NIST Cybersecurity Framework v1.1

Lookalike-domain monitoring

Demonstrate that the organization systematically detects, evaluates, and responds to lookalike domain registrations that could be exploited to impersonate the organization or deceive its users, employees, and customers.

Description

What this control does

Lookalike-domain monitoring is a continuous surveillance program that identifies and tracks domain registrations that closely resemble an organization's legitimate domains through character substitution (typosquatting), homoglyphs, combosquatting, or TLD variations. The control typically employs specialized monitoring services, WHOIS data feeds, certificate transparency logs, and DNS query analysis to detect newly registered domains that could be used for phishing, brand impersonation, or credential harvesting attacks. Organizations maintain watchlists of protected brand terms and domain patterns, receive automated alerts on suspicious registrations, and execute takedown or mitigation workflows when threats are confirmed.

Control objective

What auditing this proves

Demonstrate that the organization systematically detects, evaluates, and responds to lookalike domain registrations that could be exploited to impersonate the organization or deceive its users, employees, and customers.

Associated risks

Risks this control addresses

  • Phishing campaigns using typosquatted domains to harvest employee or customer credentials
  • Business email compromise (BEC) attacks leveraging similar-looking domains to impersonate executives or vendors
  • Malware distribution sites mimicking legitimate organizational download portals
  • Brand reputation damage from fraudulent sites claiming affiliation with the organization
  • Customer financial loss due to fake payment or support portals using lookalike domains
  • Supply chain attacks where threat actors impersonate the organization to third parties
  • Data exfiltration via attacker-controlled domains that evade allowlist-based security controls

Testing procedure

How an auditor verifies this control

  1. Obtain the organization's inventory of protected domain names, brand terms, and monitored domain patterns from the security or brand protection team.
  2. Review documentation of the lookalike-domain monitoring solution(s) in use, including vendor contracts, in-house tooling specifications, or third-party service agreements.
  3. Verify configuration settings for monitoring scope, including character substitution rules, TLD coverage, homoglyph detection, and combosquatting patterns.
  4. Examine a sample of alert records from the past 90 days, confirming that newly registered lookalike domains were detected within the vendor's stated SLA or policy-defined timeframe.
  5. Select three detected lookalike domains from alert logs and trace the organization's response workflow, including triage classification, threat assessment, and any takedown or legal actions initiated.
  6. Interview personnel responsible for monitoring alerts to confirm they understand escalation procedures, triage criteria, and coordination with legal, IT, and communications teams.
  7. Test the alerting mechanism by requesting evidence of notification delivery (email, ticketing system, SIEM integration) for recent high-severity lookalike domain detections.
  8. Review metrics or reporting dashboards showing detection volume, response times, takedown success rates, and trends over the past six months to confirm continuous operation and effectiveness measurement.
Evidence required Auditors collect configuration exports or screenshots from the lookalike-domain monitoring platform showing monitored terms and detection rules; alert logs or case management records demonstrating detection and triage of lookalike domains over a representative period; documented response procedures and evidence of executed takedown requests, WHOIS correspondence, or legal notices; and periodic reports or dashboards summarizing monitoring coverage, detection trends, and response metrics.
Pass criteria The control passes if the organization operates a continuous lookalike-domain monitoring capability covering its critical domains and brands, demonstrates timely detection of new registrations, maintains documented response procedures, and provides evidence of active triage and mitigation actions for identified threats within the past 90 days.

Where this control is tested

Audit programs including this control