MailRead Permissions Granted to Application

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])

relevantTechniques:
- T1098
name: Mail.Read Permissions Granted to Application
requiredDataConnectors:
- dataTypes:
  - AuditLogs
  connectorId: AzureActiveDirectory
entityMappings:
- 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: Account
- fieldMappings:
  - identifier: Address
    columnName: InitiatingIpAddress
  entityType: IP
triggerThreshold: 0
id: 2560515c-07d1-434e-87fb-ebe3af267760
tactics:
- Persistence
version: 1.0.4
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Microsoft Entra ID/Analytic Rules/MailPermissionsAddedToApplication.yaml
queryPeriod: 1d
kind: Scheduled
tags:
- Solorigate
- NOBELIUM
queryFrequency: 1d
severity: Medium
status: Available
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.'
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])  
triggerOperator: gt

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "workspace": {
      "type": "String"
    }
  },
  "resources": [
    {
      "apiVersion": "2024-01-01-preview",
      "id": "[concat(resourceId('Microsoft.OperationalInsights/workspaces/providers', parameters('workspace'), 'Microsoft.SecurityInsights'),'/alertRules/2560515c-07d1-434e-87fb-ebe3af267760')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/2560515c-07d1-434e-87fb-ebe3af267760')]",
      "properties": {
        "alertRuleTemplateName": "2560515c-07d1-434e-87fb-ebe3af267760",
        "customDetails": null,
        "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.'\n",
        "displayName": "Mail.Read Permissions Granted to Application",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "InitiatingUserPrincipalName",
                "identifier": "FullName"
              },
              {
                "columnName": "Name",
                "identifier": "Name"
              },
              {
                "columnName": "UPNSuffix",
                "identifier": "UPNSuffix"
              }
            ]
          },
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "InitiatingAadUserId",
                "identifier": "AadUserId"
              }
            ]
          },
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "InitiatingAppServicePrincipalId",
                "identifier": "AadUserId"
              }
            ]
          },
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "columnName": "InitiatingIpAddress",
                "identifier": "Address"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Microsoft Entra ID/Analytic Rules/MailPermissionsAddedToApplication.yaml",
        "query": "AuditLogs\n| where Category =~ \"ApplicationManagement\"\n| where ActivityDisplayName has_any (\"Add delegated permission grant\",\"Add app role assignment to service principal\")  \n| where Result =~ \"success\"\n| where tostring(InitiatedBy.user.userPrincipalName) has \"@\" or tostring(InitiatedBy.app.displayName) has \"@\"\n| mv-apply TargetResource = TargetResources on \n  (\n      where TargetResource.type =~ \"ServicePrincipal\" and array_length(TargetResource.modifiedProperties) > 0 and isnotnull(TargetResource.displayName)\n      | extend props = TargetResource.modifiedProperties,\n               Type = tostring(TargetResource.type),\n               PermissionsAddedTo = tostring(TargetResource.displayName)\n  )\n| mv-apply Property = props on \n  (\n      where Property.displayName =~ \"DelegatedPermissionGrant.Scope\"\n      | extend DisplayName = tostring(Property.displayName), Permissions = trim('\"',tostring(Property.newValue))\n  )\n| where Permissions has_any (\"Mail.Read\", \"Mail.ReadWrite\")\n| mv-apply AdditionalDetail = AdditionalDetails on \n  (\n      where AdditionalDetail.key =~ \"User-Agent\"\n      | extend InitiatingUserAgent = tostring(AdditionalDetail.value)\n  )\n| extend InitiatingAppName = tostring(InitiatedBy.app.displayName)\n| extend InitiatingAppServicePrincipalId = tostring(InitiatedBy.app.servicePrincipalId)\n| extend InitiatingUserPrincipalName = tostring(InitiatedBy.user.userPrincipalName)\n| extend InitiatingAadUserId = tostring(InitiatedBy.user.id)\n| extend InitiatingIpAddress = tostring(iff(isnotempty(InitiatedBy.user.ipAddress), InitiatedBy.user.ipAddress, InitiatedBy.app.ipAddress))\n| project-away props, TargetResource, AdditionalDetail, Property\n| join kind=leftouter(\n  AuditLogs\n  | where ActivityDisplayName has \"Consent to application\"\n  | mv-apply TargetResource = TargetResources on \n      (\n          where TargetResource.type =~ \"ServicePrincipal\"\n          | extend AppName = tostring(TargetResource.displayName),\n                   AppId = tostring(TargetResource.id)\n      )\n| project AppName, AppId, CorrelationId) on CorrelationId\n| project-away CorrelationId1\n| project-reorder TimeGenerated, OperationName, InitiatingUserPrincipalName, InitiatingAadUserId, InitiatingAppName, InitiatingAppServicePrincipalId, InitiatingIpAddress, InitiatingUserAgent, PermissionsAddedTo, Permissions, AppName, AppId, CorrelationId\n| extend Name = tostring(split(InitiatingUserPrincipalName,'@',0)[0]), UPNSuffix = tostring(split(InitiatingUserPrincipalName,'@',1)[0])\n",
        "queryFrequency": "P1D",
        "queryPeriod": "P1D",
        "severity": "Medium",
        "status": "Available",
        "subTechniques": [],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "Persistence"
        ],
        "tags": [
          "Solorigate",
          "NOBELIUM"
        ],
        "techniques": [
          "T1098"
        ],
        "templateVersion": "1.0.4",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}