Question 110
Internal hosts query random long subdomains with high entropy at steady intervals. What is the MOST appropriate analyst action based on the evidence?
Explanation
Correct Answer
Unusual high-entropy subdomain streams can carry encoded data through DNS. Triage DNS tunneling pattern.
Incorrect Answers
Rapid answer churn may indicate resilient malicious hosting rather than routine CDN use. It could help evaluate suspicious fast-flux DNS, but it would not triage DNS tunneling pattern.
Repeated failed pseudo-random lookups are common to generated rendezvous attempts. It would test DGA-driven lookup hypothesis, but it would not triage DNS tunneling pattern.
Legitimate service discovery can use TXT records and must be distinguished by context. It could help validate benign TXT query spike, but it would not triage DNS tunneling pattern.






CompTIA CySA+ (CS0-003) (CS0-003) Practice Tests