[Rule Tuning] Entra ID Protection Sign-in and User Risk Detection Rules - Filter Remediated Risk States

[terrancedejesus]

Fixes #5534

Pull Request

Issue link(s):

• [Rule Tuning] Entra ID Protection Sign-in and User Risk Detection Rules - Filter Remediated Risk States #5534

Summary - What I changed

Removes unnecessary noise from Entra ID Protection Risk Detection rules related to remediated/dismissed action taken by Entra ID Admins/Users. Please see related issue for more details.

How To Test

• Queries can be used in telemetry & TRADE stack (+1 year) to review alerts/raw events.

Checklist

• Added a label for the type of pr: bug, enhancement, schema, maintenance, Rule: New, Rule: Deprecation, Rule: Tuning, Hunt: New, or Hunt: Tuning so guidelines can be generated
• Added the meta:rapid-merge label if planning to merge within 24 hours
• Secret and sensitive material has been managed correctly
• Automated testing was updated or added to match the most common scenarios
• Documentation and comments were added for features that require explanation

Contributor checklist

• Have you signed the contributor license agreement?
• Have you followed the contributor guidelines?

[github-actions]

Rule: Tuning - Guidelines

These guidelines serve as a reminder set of considerations when tuning an existing rule.

Documentation and Context

• Detailed description of the suggested changes.
• Provide example JSON data or screenshots.
• Provide evidence of reducing benign events mistakenly identified as threats (False Positives).
• Provide evidence of enhancing detection of true threats that were previously missed (False Negatives).
• Provide evidence of optimizing resource consumption and execution time of detection rules (Performance).
• Provide evidence of specific environment factors influencing customized rule tuning (Contextual Tuning).
• Provide evidence of improvements made by modifying sensitivity by changing alert triggering thresholds (Threshold Adjustments).
• Provide evidence of refining rules to better detect deviations from typical behavior (Behavioral Tuning).
• Provide evidence of improvements of adjusting rules based on time-based patterns (Temporal Tuning).
• Provide reasoning of adjusting priority or severity levels of alerts (Severity Tuning).
• Provide evidence of improving quality integrity of our data used by detection rules (Data Quality).
• Ensure the tuning includes necessary updates to the release documentation and versioning.

Rule Metadata Checks

• updated_date matches the date of tuning PR merged.
• min_stack_version should support the widest stack versions.
• name and description should be descriptive and not include typos.
• query should be inclusive, not overly exclusive. Review to ensure the original intent of the rule is maintained.

Testing and Validation

• Validate that the tuned rule's performance is satisfactory and does not negatively impact the stack.
• Ensure that the tuned rule has a low false positive rate.

[Mikaayenson]

just double checking, since both rules now filter by azure.identityprotection.properties.activity do we still need event.action and is it correct? Do both rules use the same event action across user/signin?

[terrancedejesus]

Thanks for review @Mikaayenson.

just double checking, since both rules now filter by azure.identityprotection.properties.activity do we still need event.action and is it correct? Do both rules use the same event action across user/signin?

azure.identityprotection.properties.activity is to differentiate between sign-ins that are risky (atypical travel, token anomalies, etc.) under the Entra ID "Risk Detections" heuristics, where user is reported that Entra ID classifies a user is typically at risk. Risky users have User Risk Detection as an event.action just as users at risk do, however users at risk also have Risky user as event.action sometimes depending on what Entra ID Protection flagged it for. I kept event.action in to scope the specific alerts prompted by Entra ID Protection to user risk, pending different types of alerts in the future; but not it is not necessary to differentiate between these two rules. I do believe it is best to keep it.