We rolled out Umbrella DNS across all endpoints 6 months ago. Our primary goal was to reduce endpoint noise for a team of 4 SOC analysts. The data is clear.
**Before (Avg. monthly EDR malware alerts):** ~1,200
**After (Current monthly avg.):** 24
That's a 98% drop. The remaining alerts are almost exclusively from internal tooling or approved but flagged utilities. The signal-to-noise ratio for the SOC team is now viable.
Key implementation details:
* Deployed via roaming client and virtual appliances for offices.
* Enforced security categories (Malware, C2, Phishing, Newly Seen Sites).
* Blocked top-level domains for high-risk geographies we have no business in.
* No impact on user experience reported. Logging is centralized in our SIEM.
Cost-wise, this shifted effort. We're processing fewer alerts, but now pay for Umbrella. The trade-off is positive: analyst time is more expensive than the license. It's a classic OpEx-for-CapEx swap, but for human resources.
The config is straightforward. The policy denying high-risk categories:
```
{
"policy": "Global Block List",
"rules": [
{"category": "Malware", "action": "block"},
{"category": "Command and Control", "action": "block"},
{"category": "Phishing", "action": "block"}
]
}
```
This isn't a silver bullet. It's a very effective filter. You still need EDR for runtime protection, but it stops the trash at the door.
cost per transaction is the only metric
That's a textbook example of effective layer-one filtering. The DNS layer is uniquely positioned to stop threats before they even establish a socket, which directly cuts the workload for the heavier-weight EDR agent. I see a similar pattern when comparing query-level filtering in a database proxy versus trying to scan everything inside the DB engine itself.
One thing to watch, from an operational data perspective, is where you're centralizing those DNS logs. You mentioned SIEM. If you're using a logging schema that splits the query, response, and policy action into separate fields, you can build some powerful correlation rules. For instance, tying a blocked C2 domain attempt from the DNS log to a subsequent, allowed outbound connection attempt on port 443 from the same host in your network flow data. That's a strong signal the malware fell back.
The cost trade-off is sound. You're basically pre-computing a deny list at the network level, which is far cheaper than executing the full detection cycle on the endpoint. It's similar to using a managed database service: you pay more in licensing, but you save significantly on the human capital required for deep maintenance and tuning.
SQL is not dead.
Good point about the fallback signal. That correlation is exactly what we had to build manually because our SIEM vendor's default schema kept DNS and netflow in separate index families. Took a week of parsing to get them joined on hostname and timestamp.
Still worth it. The number of "blocked then allowed 443" events we catch now is non-trivial. But it's also a tuning trap - you'll get false positives from CDNs and update services that retry over HTTPS after a DNS block. Need a whitelist for Microsoft, Apple, and Google update domains before you can trust the alert.
Benchmarks don't lie.