Mail.Read Permissions Granted to Application

id: 2560515c-07d1-434e-87fb-ebe3af267760
name: Mail.Read Permissions Granted to Application
description: |
  'This query look for applications that have been granted (Delegated or App/Role) permissions to Read Mail (Permissions field has Mail.Read) and subsequently has been consented to. This can help identify applications that have been abused to gain access to mailboxes.'
severity: Medium
requiredDataConnectors:
  - connectorId: AzureActiveDirectory
    dataTypes:
      - AuditLogs
queryFrequency: 1d
queryPeriod: 1d
triggerOperator: gt
triggerThreshold: 0
status: Available
tactics:
  - Persistence
relevantTechniques:
  - T1098
tags:
  - Solorigate
  - NOBELIUM
query: |
  AuditLogs
  | where Category =~ "ApplicationManagement"
  | where ActivityDisplayName has_any ("Add delegated permission grant","Add app role assignment to service principal")  
  | where Result =~ "success"
  | where tostring(InitiatedBy.user.userPrincipalName) has "@" or tostring(InitiatedBy.app.displayName) has "@"
  | mv-apply TargetResource = TargetResources on 
    (
        where TargetResource.type =~ "ServicePrincipal" and array_length(TargetResource.modifiedProperties) > 0 and isnotnull(TargetResource.displayName)
        | extend props = TargetResource.modifiedProperties,
                 Type = tostring(TargetResource.type),
                 PermissionsAddedTo = tostring(TargetResource.displayName)
    )
  | mv-apply Property = props on 
    (
        where Property.displayName =~ "DelegatedPermissionGrant.Scope"
        | extend DisplayName = tostring(Property.displayName), Permissions = trim('"',tostring(Property.newValue))
    )
  | where Permissions has_any ("Mail.Read", "Mail.ReadWrite")
  | mv-apply AdditionalDetail = AdditionalDetails on 
    (
        where AdditionalDetail.key =~ "User-Agent"
        | extend InitiatingUserAgent = tostring(AdditionalDetail.value)
    )
  | 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))
  | project-away props, TargetResource, AdditionalDetail, Property
  | join kind=leftouter(
    AuditLogs
    | where ActivityDisplayName has "Consent to application"
    | mv-apply TargetResource = TargetResources on 
        (
            where TargetResource.type =~ "ServicePrincipal"
            | extend AppName = tostring(TargetResource.displayName),
                     AppId = tostring(TargetResource.id)
        )
  | project AppName, AppId, CorrelationId) on CorrelationId
  | project-away CorrelationId1
  | project-reorder TimeGenerated, OperationName, InitiatingUserPrincipalName, InitiatingAadUserId, InitiatingAppName, InitiatingAppServicePrincipalId, InitiatingIpAddress, InitiatingUserAgent, PermissionsAddedTo, Permissions, AppName, AppId, CorrelationId
  | extend Name = tostring(split(InitiatingUserPrincipalName,'@',0)[0]), UPNSuffix = tostring(split(InitiatingUserPrincipalName,'@',1)[0])
entityMappings:
  - entityType: Account
    fieldMappings:
      - identifier: FullName
        columnName: InitiatingUserPrincipalName
      - identifier: Name
        columnName: Name
      - identifier: UPNSuffix
        columnName: UPNSuffix
  - entityType: Account
    fieldMappings:
      - identifier: AadUserId
        columnName: InitiatingAadUserId
  - entityType: Account
    fieldMappings:
      - identifier: AadUserId
        columnName: InitiatingAppServicePrincipalId
  - entityType: IP
    fieldMappings:
      - identifier: Address
        columnName: InitiatingIpAddress
version: 1.0.4
kind: Scheduled