A security operations team is using Cortex XSIAM to track the 'Mean Time to Detect' (MTTD) metric for endpoint alerts. The team defines MTTD as the time between the initial malicious activity on an endpoint and the creation of an alert in Cortex XSIAM. The architect needs to ensure that the metric is calculated consistently across all endpoint alerts. Which Cortex XSIAM data source should the architect use to obtain the timestamp of the initial malicious activity?
Cortex XSIAM ingests endpoint telemetry that includes event timestamps reflecting when activities occurred on the endpoint. The earliest relevant event timestamp for the malicious activity provides the starting point for MTTD. This data is available in the endpoint data sources and can be correlated with alert creation time to compute the true detection latency.
Why this answer
Accurate MTTD calculation requires the timestamp of the initial malicious activity, which is captured in endpoint telemetry events ingested by Cortex XSIAM. The 'Event Timestamp' from EDR or endpoint logs provides this ground truth. Correlating it with the alert creation time yields the true detection latency, ensuring consistent measurement across all endpoint alerts.
Exam trap
The trap here is using the alert creation time as the start of the detection window, which measures the wrong interval and ignores when the malicious activity actually began.