Cross-tenant Access Settings Organization Outbound Collaboration Settings Changed

// In User & Groups and in Applications, the following "AccessType" values in columns PremodifiedOutboundSettings and ModifiedOutboundSettings are interpreted accordingly
// When Access Type in premodified outbound settings value was 1 that means that the initial access was allowed. When Access Type in premodified outbound settings value was 2 that means that the initial access was blocked.
// When Access Type in modified outbound settings value is 1 that means that now access is allowed. When Access Type in modified outbound settings value is 2 that means that now access is blocked.
AuditLogs
| where OperationName has "Update a partner cross-tenant access setting"
| mv-apply TargetResource = TargetResources on
  (
      where TargetResource.type =~ "Policy"
      | extend Properties = TargetResource.modifiedProperties
  )
| mv-apply Property = Properties on
  (
      where Property.displayName =~ "b2bCollaborationOutbound"
      | extend PremodifiedOutboundSettings = trim('"',tostring(Property.oldValue)),
               ModifiedOutboundSettings = trim(@'"',tostring(Property.newValue))
  )
| where PremodifiedOutboundSettings != ModifiedOutboundSettings
| extend InitiatingAppName = tostring(InitiatedBy.app.displayName)
| extend InitiatingAppServicePrincipalId = tostring(InitiatedBy.app.servicePrincipalId)
| extend InitiatingUserPrincipalName = tostring(InitiatedBy.user.userPrincipalName)
| extend InitiatingAadUserId = tostring(InitiatedBy.user.id)
| extend InitiatingIpAddress = tostring(iff(isnotempty(InitiatedBy.user.ipAddress), InitiatedBy.user.ipAddress, InitiatedBy.app.ipAddress))
| extend InitiatingAccountName = tostring(split(InitiatingUserPrincipalName, "@")[0]), InitiatingAccountUPNSuffix = tostring(split(InitiatingUserPrincipalName, "@")[1])

description: |
    'Organizations are added in the Cross-tenant Access Settings to control communication inbound or outbound for users and applications. This detection notifies when Organization Outbound Collaboration Settings are changed for "Users & Groups" and for "Applications".'
version: 1.1.1
triggerThreshold: 0
tactics:
- InitialAccess
- Persistence
- Discovery
queryPeriod: 2d
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Microsoft Entra ID/Analytic Rules/Cross-tenantAccessSettingsOrganizationOutboundCollaborationSettingsChanged.yaml
triggerOperator: gt
status: Available
id: 229f71ba-d83b-42a5-b83b-11a641049ed1
name: Cross-tenant Access Settings Organization Outbound Collaboration Settings Changed
queryFrequency: 2d
severity: Medium
kind: Scheduled
entityMappings:
- fieldMappings:
  - columnName: InitiatingAppName
    identifier: Name
  - columnName: InitiatingAppServicePrincipalId
    identifier: AadUserId
  entityType: Account
- fieldMappings:
  - columnName: InitiatingUserPrincipalName
    identifier: FullName
  - columnName: InitiatingAccountName
    identifier: Name
  - columnName: InitiatingAccountUPNSuffix
    identifier: UPNSuffix
  entityType: Account
- fieldMappings:
  - columnName: InitiatingAadUserId
    identifier: AadUserId
  entityType: Account
- fieldMappings:
  - columnName: InitiatingIpAddress
    identifier: Address
  entityType: IP
relevantTechniques:
- T1078.004
- T1136.003
- T1087.004
query: |
  // In User & Groups and in Applications, the following "AccessType" values in columns PremodifiedOutboundSettings and ModifiedOutboundSettings are interpreted accordingly
  // When Access Type in premodified outbound settings value was 1 that means that the initial access was allowed. When Access Type in premodified outbound settings value was 2 that means that the initial access was blocked.
  // When Access Type in modified outbound settings value is 1 that means that now access is allowed. When Access Type in modified outbound settings value is 2 that means that now access is blocked.
  AuditLogs
  | where OperationName has "Update a partner cross-tenant access setting"
  | mv-apply TargetResource = TargetResources on
    (
        where TargetResource.type =~ "Policy"
        | extend Properties = TargetResource.modifiedProperties
    )
  | mv-apply Property = Properties on
    (
        where Property.displayName =~ "b2bCollaborationOutbound"
        | extend PremodifiedOutboundSettings = trim('"',tostring(Property.oldValue)),
                 ModifiedOutboundSettings = trim(@'"',tostring(Property.newValue))
    )
  | where PremodifiedOutboundSettings != ModifiedOutboundSettings
  | extend InitiatingAppName = tostring(InitiatedBy.app.displayName)
  | extend InitiatingAppServicePrincipalId = tostring(InitiatedBy.app.servicePrincipalId)
  | extend InitiatingUserPrincipalName = tostring(InitiatedBy.user.userPrincipalName)
  | extend InitiatingAadUserId = tostring(InitiatedBy.user.id)
  | extend InitiatingIpAddress = tostring(iff(isnotempty(InitiatedBy.user.ipAddress), InitiatedBy.user.ipAddress, InitiatedBy.app.ipAddress))
  | extend InitiatingAccountName = tostring(split(InitiatingUserPrincipalName, "@")[0]), InitiatingAccountUPNSuffix = tostring(split(InitiatingUserPrincipalName, "@")[1])  
requiredDataConnectors:
- dataTypes:
  - AuditLogs
  connectorId: AzureActiveDirectory