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Create azure_ad_cross_tenant_b2b_collab_signin.yml #5233

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Create azure_ad_cross_tenant_b2b_collab_signin.yml #5233

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Create azure_ad_cross_tenant_b2b_collab_signin.yml
whichbuffer Mar 15, 2025
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Update azure_ad_cross_tenant_b2b_collab_signin.yml
whichbuffer Mar 15, 2025
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22 changes: 22 additions & 0 deletions rules/cloud/azure/signin_logs/azure_ad_cross_tenant_b2b_collab_signin.yml
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title: Suspicious Sign-In with Cross-Tenant B2B Collaboration
id: 601acb6f-bf56-4029-80fd-02bacff2b5c4
description: Detects sign-in activity by external users with a CrossTenant B2B Collaboration context, which could indicate lateral movement using a newly provisioned account.
status: test
author: Arda Buyukkaya (EclecticIQ)
date: 2025-03-15
references:
- https://learn.microsoft.com/en-us/entra/identity/monitoring-health/reference-audit-activities
- https://blog.eclecticiq.com/ransomware-in-the-cloud-scattered-spider-targeting-insurance-and-financial-industries
- https://www.xintra.org/blog/lateral-movement-entraid-cross-tenant-synchronization
tags:
- attack.lateral-movement
logsource:
product: azure
service: signinlogs
detection:
selection:
CrossTenantAccessType: "b2bCollaboration"
condition: selection
falsepositives:
- Legitimate external partner sign-ins
level: medium
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