Cross-tenant Access Settings Organization Outbound Collaboration Settings Changed

id: 229f71ba-d83b-42a5-b83b-11a641049ed1
name: Cross-tenant Access Settings Organization Outbound Collaboration Settings Changed
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".'
severity: Medium
requiredDataConnectors:
  - connectorId: AzureActiveDirectory
    dataTypes:
      - AuditLogs
queryFrequency: 2d
queryPeriod: 2d
triggerOperator: gt
triggerThreshold: 0
status: Available
tactics:
  - InitialAccess
  - Persistence
  - Discovery
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])
entityMappings:
  - entityType: Account
    fieldMappings:
      - identifier: Name
        columnName: InitiatingAppName
      - identifier: AadUserId
        columnName: InitiatingAppServicePrincipalId
  - entityType: Account
    fieldMappings:
      - identifier: FullName
        columnName: InitiatingUserPrincipalName
      - identifier: Name
        columnName: InitiatingAccountName
      - identifier: UPNSuffix
        columnName: InitiatingAccountUPNSuffix
  - entityType: Account
    fieldMappings:
      - identifier: AadUserId
        columnName: InitiatingAadUserId
  - entityType: IP
    fieldMappings:
      - identifier: Address
        columnName: InitiatingIpAddress
version: 1.1.1
kind: Scheduled