Question 270
A network and security operations handoff reports: Threat intelligence identifies an active command-and-control domain, but requests from affected devices are only logged rather than denied. Which preventive control best reduces recurrence?
Explanation
Correct Answer
This safeguard mitigates advanced threat protection domain block: Set expiry and review processes for custom threat indicators and record their supporting intelligence source. The risk being controlled is: A detection list without a corresponding effective threat policy action provides visibility but not the desired prevention. A safeguard for an unrelated failure would not address it.
Incorrect Answers
An incomplete threat policy scope can extend an intended malicious-indicator block to ordinary encrypted business traffic. “Require review of source, destination, service and action fields before enabling inherited threat rules” would remedy that alternative situation, but it would not correct the present issue: a detection list without a corresponding effective threat policy action provides visibility but not the desired prevention.
“Review IPS rule actions after converting detection-only test deployments into production prevention policies” is the supported response when detection and blocking are distinct IPS actions, so a signature match is not proof that inline traffic was prevented. Here the decisive response is “Set expiry and review processes for custom threat indicators and record their supporting intelligence source”, so that different intervention does not meet the stated requirement.
Firewall matching depends on protocol as well as destination port; blocking only one transport does not cover every DNS flow. “Use transport-aware firewall test cases whenever restricting common dual-protocol application services” applies to that other condition. The reported evidence is threat intelligence identifies an active command-and-control domain, but requests from affected devices are only logged rather than denied; this alternative would address the wrong dependency.