[New Rule] Microsoft Entra ID Impossible Travel Sign-in

[terrancedejesus]

Pull Request

Issue link(s):

• https://github.com/elastic/ia-trade-team/issues/917

Summary - What I changed

Adds an impossible travel detection rule for Entra ID Sign-In logs. Matches on AitM phishing kits from recent research. Includes >=2 regions or countries as kits may proxy through the same country as phished user. Relies on GeoIP enrichments to mathematically identify anomalies between lon/lan distance and travel time.

How To Test

Query can be run on the TRADE stack (see above) or against any telemetry stack with the logs-azure.signinlogs-* data stream. Lookback duration materially affects results because travel_kmh = distance_km × 60 / window_minutes, a longer lookback inflates the time denominator faster than the geographic spread, lowering implied speeds and dropping matches. Empirically a 24h lookback may surface ~8 candidates that drop to ~1 over 7d as normal global activity dilutes the speed calculation.

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: New - Guidelines

These guidelines serve as a reminder set of considerations when proposing a new rule.

Documentation and Context

• Detailed description of the rule.
• List any new fields required in ECS/data sources.
• Link related issues or PRs.
• Include references.

Rule Metadata Checks

• creation_date matches the date of creation PR initially merged.
• min_stack_version should support the widest stack versions.
• name and description should be descriptive and not include typos.
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• min_stack_comments and min_stack_version should be included if the rule is only compatible starting from a specific stack version.
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• integration should align with the index. If the integration is newly introduced, ensure the manifest, schemas, and new_rule.yaml template are updated.
• setup should include the necessary steps to configure the integration.
• note should include any additional information (e.g. Triage and analysis investigation guides, timeline templates).
• tags should be relevant to the threat and align/added to the EXPECTED_RULE_TAGS in the definitions.py file.
• threat, techniques, and subtechniques should map to ATT&CK always if possible.

New BBR Rules

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Testing and Validation

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