elastic / detection-rules

https://www.elastic.co/guide/en/security/current/detection-engine-overview.html
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[Rule Tunings] Change `from` field to prevent double alerts #3868

Closed imays11 closed 2 months ago

imays11 commented 3 months ago

Issue

Summary

This tuning is to change the from field to now-6m for rules that havenow-10m set and the interval left as default the 5m This results in the potential for a single event to produce double alerts by being triggered within 2 seperate execution windows.

This happened in my stack with the follow event, note event.created is 22:40:30.433

Screenshot 2024-07-06 at 1 10 59 AM

It triggered 2 alerts at 2 separate detection times 22:45:30.463 and 22:50:33.497

Screenshot 2024-07-06 at 1 14 30 AM

The rule execution times that match with these detection times are shown below, the event.created stamp falls just within both of these 10m lookback windows

Screenshot 2024-07-06 at 1 15 27 AM