Question 1120
During a planned service expansion at Prairie Health Network, engineers say that they resolved this finding: A compromised endpoint sends unusually long encoded DNS queries to attacker-controlled domains outside normal resolution behavior. Which result provides the STRONGEST acceptance evidence?
Explanation
Correct Answer
A controlled tunneling simulation raises an event while routine DNS requests work. This is the decisive evidence for the original problem: A compromised endpoint sends unusually long encoded DNS queries to attacker-controlled domains outside normal resolution behavior. It verifies that the intended corrective control—Detect and constrain DNS tunneling using query anomaly monitoring and DNS-layer policy—works in the relevant environment; a completed change ticket alone would not prove the outcome at Prairie Health Network.
Incorrect Answers
Normal time synchronization works and the unexpected transfer path is blocked. This would be relevant evidence for a different failure: A host sends repeated NTP packets with unusual application-sized content to an external endpoint, usually addressed by Detect protocol-abuse deviations and restrict NTP to approved time sources. It does not demonstrate that the current problem at Prairie Health Network was resolved. The specific required evidence is: A controlled tunneling simulation raises an event while routine DNS requests work.
The covert-transfer test creates an alert and cannot move meaningful protected data. This would be relevant evidence for a different failure: A malicious process attempts to leak data through ICMP payloads rather than common web ports, usually addressed by Monitor unusual ICMP volume and payload patterns and limit unneeded egress traffic. It does not demonstrate that the current problem at Prairie Health Network was resolved. The specific required evidence is: A controlled tunneling simulation raises an event while routine DNS requests work.
Unapproved outbound file-transfer traffic is denied and correlated with source activity. This would be relevant evidence for a different failure: An internal server opens unexpected outbound SSH/SCP sessions to unknown Internet destinations overnight, usually addressed by Apply egress controls and investigate host and flow telemetry for unauthorized transfer. It does not demonstrate that the current problem at Prairie Health Network was resolved. The specific required evidence is: A controlled tunneling simulation raises an event while routine DNS requests work.