Notifications
Clear all
Topic starter
06/09/2026 9:02 am
TL;DR: DNS filtering intercepts malicious resolution requests before a connection is established, helping block phishing domains, malware command-and-control traffic, DNS tunneling, and newly registered domains, according to CyberFOX. Network teams should treat DNS as a preventative control layer, not just a routing function, because trust at resolution time is now an attack surface.
NHIMG editorial — based on content published by CyberFOX: DNS Security and DNS Filtering: How Organizations Can Prevent Threats at the Network Level
Questions worth separating out
Q: How should security teams implement DNS filtering across remote and office users?
A: Start with a policy that follows the user and device, not the subnet.
Q: Why does DNS filtering reduce phishing and malware risk so early?
A: Because it denies the lookup that makes the connection possible.
Q: What are the signs that DNS filtering is not covering enough of the environment?
A: Look for uneven block coverage across users, devices, and locations, plus a lack of logs explaining which domains were denied and why.
Practitioner guidance
- Treat DNS as an enforcement point Place DNS filtering in the path of every outbound resolution request so malicious destinations are blocked before a session forms, including roaming devices outside the office network.
- Prioritise detection for DNS tunneling patterns Tune monitoring for unusual subdomain length, high query frequency, and repeated lookups to new or low-reputation domains, then route those events into investigation workflows.
- Apply separate policy by user and device group Use granular rules for finance, engineering, contractors, and unmanaged endpoints so high-risk populations do not inherit a single flat DNS policy.
What's in the full article
CyberFOX's full article covers the operational detail this post intentionally leaves for the source:
- Platform-level guidance on IPv6 coverage, AI-driven pattern recognition, and how those capabilities are configured in practice
- Policy design examples for users, groups, devices, and locations that go beyond the governance discussion here
- Implementation detail on roaming protection for remote workers and unmanaged network conditions
- Reporting and dashboard outputs that security teams can use for operational monitoring and compliance evidence
👉 Read CyberFOX's guide to DNS security and DNS filtering →
DNS filtering: what it means for network security teams now?
Explore further
06/09/2026 9:02 am
DNS filtering is a trust-decision control, not just a blocklist. The security value comes from deciding whether a destination should be reachable before the connection exists. That places DNS policy closer to access governance than to simple web filtering. For programmes that already think in terms of allow, deny, and verification, DNS becomes another enforcement layer in the access path.
A question worth separating out:
Q: What happens when DNS security is left to perimeter tools alone?
A: Controls become easy to bypass when users work off-network or when malware uses permitted DNS traffic to reach attacker infrastructure. Perimeter-only inspection also misses the governance value of policy consistency, because the same user may be protected in one location and exposed in another.
👉 Read our full editorial: DNS filtering is becoming a core network-level control against abuse
