DNS Spy
Top 10 DNS Attacks & How To Prevent Them
DNS attacks are a significant cybersecurity threat, as attackers exploit vulnerabilities in the Domain Name System to redirect users, disrupt services, or steal sensitive information. This guide covers the top DNS attack types and how to mitigate them.
1. DNS Spoofing (Cache Poisoning)
How It Works:
Attackers inject malicious DNS records into a resolver’s cache, redirecting users to fraudulent websites.
Prevention:
Use DNSSEC to authenticate DNS responses.
Configure resolvers to reject suspicious responses.
Regularly flush DNS caches.
2. DDoS Attacks on DNS Servers
How It Works:
Attackers overwhelm DNS servers with excessive queries, causing outages.
Prevention:
Deploy Anycast DNS for load distribution.
Use rate limiting and traffic filtering.
Implement dedicated DDoS protection services.
3. DNS Hijacking
How It Works:
Attackers modify DNS settings to redirect traffic to malicious servers.
Prevention:
Use strong registrar account passwords and enable two-factor authentication.
Restrict DNS setting changes to authorized personnel.
Monitor DNS records for unauthorized modifications.
4. NXDOMAIN Attack
How It Works:
Attackers flood a DNS resolver with queries for nonexistent domains, exhausting resources.
Prevention:
Implement rate limiting on recursive queries.
Use Response Rate Limiting (RRL).
Block known malicious sources.
5. Phantom Domain Attack
How It Works:
Attackers set up slow-responding domains to tie up DNS resolvers, causing performance degradation.
Prevention:
Configure resolvers to limit query retries.
Monitor slow-query trends and block abusive domains.
6. Random Subdomain Attack
How It Works:
Attackers generate massive numbers of subdomain queries to overwhelm authoritative DNS servers.
Prevention:
Implement rate limiting and query filtering.
Deploy DNS firewalls to detect and block patterns of abuse.
7. Domain Locking & Registrar Hijacking
How It Works:
Attackers attempt to transfer domain ownership or modify records by compromising registrar accounts.
Prevention:
Enable domain locking at the registrar level.
Use WHOIS protection and monitoring services.
Enable registrar-level two-factor authentication.
8. Man-in-the-Middle (MitM) DNS Attacks
How It Works:
Attackers intercept and modify DNS responses to redirect users.
Prevention:
Use DNS over HTTPS (DoH) or DNS over TLS (DoT) for encryption.
Implement strict security policies for DNS queries.
Avoid using unsecured public DNS resolvers.
9. Tunneling via DNS (DNS Tunneling)
How It Works:
Attackers encode malicious payloads into DNS queries to bypass security controls.
Prevention:
Monitor DNS traffic for unusual query patterns.
Use deep packet inspection (DPI) to detect tunneling attempts.
Block unnecessary external DNS queries.
10. Registrar & DNS Provider Compromise
How It Works:
Attackers gain access to DNS providers or registrars, altering domain configurations.
Prevention:
Choose reputable DNS providers with strong security policies.
Enable multi-factor authentication (MFA) on all DNS accounts.
Regularly audit DNS configurations and logs.
Conclusion
DNS security is critical to preventing cyberattacks that disrupt operations and compromise data integrity. Implementing DNSSEC, traffic filtering, encryption protocols, and monitoring tools can significantly reduce the risk of DNS-related threats.