full_access_as_app Granted To Application

AuditLogs
| where LoggedByService =~ "Core Directory"
| where Category =~ "ApplicationManagement"
| where OperationName =~ "Consent to application"
| where TargetResources has "full_access_as_app"
| mv-expand TargetResources
| extend OAuthAppName = TargetResources.displayName
| extend ModifiedProperties = TargetResources.modifiedProperties 
| mv-apply Property = ModifiedProperties on 
  (
      where Property.displayName =~ "ConsentContext.isAdminConsent"
      | extend AdminConsent = tostring(Property.newValue)
  )
| mv-apply Property = ModifiedProperties on 
  (
      where Property.displayName =~ "ConsentAction.Permissions"
      | extend Permissions = tostring(Property.newValue)
  )
| mv-apply Property = ModifiedProperties on 
  (
      where Property.displayName =~ "TargetId.ServicePrincipalNames"
      | extend AppId = tostring(Property.newValue)
  )
| mv-apply Property = AdditionalDetails on 
  (
      where Property.key =~ "User-Agent"
      | extend InitiatingUserAgent = replace('"', '', tostring(Property.value))
  )
| project-away Property
| parse Permissions with * "ConsentType: " GrantConsentType ", Scope: " GrantScope1 "," *
| where GrantScope1 =~ "full_access_as_app"
| 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-reorder TimeGenerated, OAuthAppName, AppId, AdminConsent, Permissions, InitiatingUserPrincipalName, InitiatingAadUserId, InitiatingAppName, InitiatingAppServicePrincipalId, InitiatingIpAddress, InitiatingUserAgent, GrantScope1, GrantConsentType
| extend GrantInitiatedBy = tostring(iff(isnotempty(InitiatingUserPrincipalName), InitiatingUserPrincipalName, InitiatingAppName))
| extend Name = split(InitiatingUserPrincipalName, "@")[0], UPNSuffix = split(InitiatingUserPrincipalName, "@")[1]

queryPeriod: 1h
requiredDataConnectors:
- connectorId: AzureActiveDirectory
  dataTypes:
  - AuditLogs
triggerThreshold: 0
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Microsoft Entra ID/Analytic Rules/ExchangeFullAccessGrantedToApp.yaml
tactics:
- DefenseEvasion
triggerOperator: gt
alertDetailsOverride:
  alertDisplayNameFormat: User or App {{GrantInitiatedBy}} granted full_access_as_app to {{OAuthAppName}}
  alertDescriptionFormat: |
    This detection looks for the full_access_as_app permission being granted to an OAuth application with Admin Consent.
    This permission provide access to all Exchange mailboxes via the EWS API can could be exploited to access sensitive data 
    by being added to a compromised application. The application granted this permission should be reviewed to ensure that it 
    is absolutely necessary for the applications function.
    In this case {{GrantInitiatedBy}} granted full_access_as_app to {{OAuthAppName}} from {{InitiatingIpAddress}}
    Ref: https://learn.microsoft.com/graph/auth-limit-mailbox-access    
severity: Medium
name: full_access_as_app Granted To Application
relevantTechniques:
- T1550.001
customDetails:
  OAuthAppId: AppId
  UserAgent: InitiatingUserAgent
  OAuthApplication: OAuthAppName
query: |
  AuditLogs
  | where LoggedByService =~ "Core Directory"
  | where Category =~ "ApplicationManagement"
  | where OperationName =~ "Consent to application"
  | where TargetResources has "full_access_as_app"
  | mv-expand TargetResources
  | extend OAuthAppName = TargetResources.displayName
  | extend ModifiedProperties = TargetResources.modifiedProperties 
  | mv-apply Property = ModifiedProperties on 
    (
        where Property.displayName =~ "ConsentContext.isAdminConsent"
        | extend AdminConsent = tostring(Property.newValue)
    )
  | mv-apply Property = ModifiedProperties on 
    (
        where Property.displayName =~ "ConsentAction.Permissions"
        | extend Permissions = tostring(Property.newValue)
    )
  | mv-apply Property = ModifiedProperties on 
    (
        where Property.displayName =~ "TargetId.ServicePrincipalNames"
        | extend AppId = tostring(Property.newValue)
    )
  | mv-apply Property = AdditionalDetails on 
    (
        where Property.key =~ "User-Agent"
        | extend InitiatingUserAgent = replace('"', '', tostring(Property.value))
    )
  | project-away Property
  | parse Permissions with * "ConsentType: " GrantConsentType ", Scope: " GrantScope1 "," *
  | where GrantScope1 =~ "full_access_as_app"
  | 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-reorder TimeGenerated, OAuthAppName, AppId, AdminConsent, Permissions, InitiatingUserPrincipalName, InitiatingAadUserId, InitiatingAppName, InitiatingAppServicePrincipalId, InitiatingIpAddress, InitiatingUserAgent, GrantScope1, GrantConsentType
  | extend GrantInitiatedBy = tostring(iff(isnotempty(InitiatingUserPrincipalName), InitiatingUserPrincipalName, InitiatingAppName))
  | extend Name = split(InitiatingUserPrincipalName, "@")[0], UPNSuffix = split(InitiatingUserPrincipalName, "@")[1]  
queryFrequency: 1h
id: 54e22fed-0ec6-4fb2-8312-2a3809a93f63
status: Available
kind: Scheduled
entityMappings:
- 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: Account
- fieldMappings:
  - columnName: InitiatingIpAddress
    identifier: Address
  entityType: IP
version: 1.0.2
description: |
  'This detection looks for the full_access_as_app permission being granted to an OAuth application with Admin Consent.
  This permission provide access to all Exchange mailboxes via the EWS API can could be exploited to access sensitive data by being added to a compromised application. The application granted this permission should be reviewed to ensure that it is absolutely necessary for the applications function.
  Ref: https://learn.microsoft.com/graph/auth-limit-mailbox-access'  

{
  "$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/54e22fed-0ec6-4fb2-8312-2a3809a93f63')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/54e22fed-0ec6-4fb2-8312-2a3809a93f63')]",
      "properties": {
        "alertDetailsOverride": {
          "alertDescriptionFormat": "This detection looks for the full_access_as_app permission being granted to an OAuth application with Admin Consent.\nThis permission provide access to all Exchange mailboxes via the EWS API can could be exploited to access sensitive data \nby being added to a compromised application. The application granted this permission should be reviewed to ensure that it \nis absolutely necessary for the applications function.\nIn this case {{GrantInitiatedBy}} granted full_access_as_app to {{OAuthAppName}} from {{InitiatingIpAddress}}\nRef: https://learn.microsoft.com/graph/auth-limit-mailbox-access\n",
          "alertDisplayNameFormat": "User or App {{GrantInitiatedBy}} granted full_access_as_app to {{OAuthAppName}}"
        },
        "alertRuleTemplateName": "54e22fed-0ec6-4fb2-8312-2a3809a93f63",
        "customDetails": {
          "OAuthAppId": "AppId",
          "OAuthApplication": "OAuthAppName",
          "UserAgent": "InitiatingUserAgent"
        },
        "description": "'This detection looks for the full_access_as_app permission being granted to an OAuth application with Admin Consent.\nThis permission provide access to all Exchange mailboxes via the EWS API can could be exploited to access sensitive data by being added to a compromised application. The application granted this permission should be reviewed to ensure that it is absolutely necessary for the applications function.\nRef: https://learn.microsoft.com/graph/auth-limit-mailbox-access'\n",
        "displayName": "full_access_as_app 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/ExchangeFullAccessGrantedToApp.yaml",
        "query": "AuditLogs\n| where LoggedByService =~ \"Core Directory\"\n| where Category =~ \"ApplicationManagement\"\n| where OperationName =~ \"Consent to application\"\n| where TargetResources has \"full_access_as_app\"\n| mv-expand TargetResources\n| extend OAuthAppName = TargetResources.displayName\n| extend ModifiedProperties = TargetResources.modifiedProperties \n| mv-apply Property = ModifiedProperties on \n  (\n      where Property.displayName =~ \"ConsentContext.isAdminConsent\"\n      | extend AdminConsent = tostring(Property.newValue)\n  )\n| mv-apply Property = ModifiedProperties on \n  (\n      where Property.displayName =~ \"ConsentAction.Permissions\"\n      | extend Permissions = tostring(Property.newValue)\n  )\n| mv-apply Property = ModifiedProperties on \n  (\n      where Property.displayName =~ \"TargetId.ServicePrincipalNames\"\n      | extend AppId = tostring(Property.newValue)\n  )\n| mv-apply Property = AdditionalDetails on \n  (\n      where Property.key =~ \"User-Agent\"\n      | extend InitiatingUserAgent = replace('\"', '', tostring(Property.value))\n  )\n| project-away Property\n| parse Permissions with * \"ConsentType: \" GrantConsentType \", Scope: \" GrantScope1 \",\" *\n| where GrantScope1 =~ \"full_access_as_app\"\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-reorder TimeGenerated, OAuthAppName, AppId, AdminConsent, Permissions, InitiatingUserPrincipalName, InitiatingAadUserId, InitiatingAppName, InitiatingAppServicePrincipalId, InitiatingIpAddress, InitiatingUserAgent, GrantScope1, GrantConsentType\n| extend GrantInitiatedBy = tostring(iff(isnotempty(InitiatingUserPrincipalName), InitiatingUserPrincipalName, InitiatingAppName))\n| extend Name = split(InitiatingUserPrincipalName, \"@\")[0], UPNSuffix = split(InitiatingUserPrincipalName, \"@\")[1]\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "PT1H",
        "severity": "Medium",
        "status": "Available",
        "subTechniques": [
          "T1550.001"
        ],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "DefenseEvasion"
        ],
        "techniques": [
          "T1550"
        ],
        "templateVersion": "1.0.2",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}