New access credential added to Application or Service Principal

AuditLogs
| where OperationName has_any ("Add service principal", "Certificates and secrets management") // captures "Add service principal", "Add service principal credentials", and "Update application - Certificates and secrets management" events
| where Result =~ "success"
| mv-expand target = TargetResources
| where tostring(InitiatedBy.user.userPrincipalName) has "@" or tostring(InitiatedBy.app.displayName) has "@"
| extend targetDisplayName = tostring(TargetResources[0].displayName)
| extend targetId = tostring(TargetResources[0].id)
| extend targetType = tostring(TargetResources[0].type)
| extend keyEvents = TargetResources[0].modifiedProperties
| mv-expand keyEvents
| where keyEvents.displayName =~ "KeyDescription"
| extend new_value_set = parse_json(tostring(keyEvents.newValue))
| extend old_value_set = parse_json(tostring(keyEvents.oldValue))
| where old_value_set != "[]"
| extend diff = set_difference(new_value_set, old_value_set)
| where isnotempty(diff)
| parse diff with * "KeyIdentifier=" keyIdentifier:string ",KeyType=" keyType:string ",KeyUsage=" keyUsage:string ",DisplayName=" keyDisplayName:string "]" *
| where keyUsage == "Verify"  or keyUsage == ""
| extend UserAgent = iff(AdditionalDetails[0].key == "User-Agent",tostring(AdditionalDetails[0].value),"")
| extend InitiatingUserOrApp = iff(isnotempty(InitiatedBy.user.userPrincipalName),tostring(InitiatedBy.user.userPrincipalName), tostring(InitiatedBy.app.displayName))
| extend InitiatingIpAddress = iff(isnotempty(InitiatedBy.user.ipAddress), tostring(InitiatedBy.user.ipAddress), tostring(InitiatedBy.app.ipAddress))
// The below line is currently commented out but Microsoft Sentinel users can modify this query to show only Application or only Service Principal events in their environment
//| where targetType =~ "Application" // or targetType =~ "ServicePrincipal"
| project-away diff, new_value_set, old_value_set
| project-reorder TimeGenerated, OperationName, InitiatingUserOrApp, InitiatingIpAddress, UserAgent, targetDisplayName, targetId, targetType, keyDisplayName, keyType, keyUsage, keyIdentifier, CorrelationId, TenantId
| extend timestamp = TimeGenerated, AccountCustomEntity = InitiatingUserOrApp, IPCustomEntity = InitiatingIpAddress

version: 1.1.0
status: Available
queryFrequency: 1h
requiredDataConnectors:
- connectorId: AzureActiveDirectory
  dataTypes:
  - AuditLogs
entityMappings:
- fieldMappings:
  - columnName: AccountCustomEntity
    identifier: FullName
  entityType: Account
- fieldMappings:
  - columnName: IPCustomEntity
    identifier: Address
  entityType: IP
kind: Scheduled
queryPeriod: 1h
severity: Medium
query: |
  AuditLogs
  | where OperationName has_any ("Add service principal", "Certificates and secrets management") // captures "Add service principal", "Add service principal credentials", and "Update application - Certificates and secrets management" events
  | where Result =~ "success"
  | mv-expand target = TargetResources
  | where tostring(InitiatedBy.user.userPrincipalName) has "@" or tostring(InitiatedBy.app.displayName) has "@"
  | extend targetDisplayName = tostring(TargetResources[0].displayName)
  | extend targetId = tostring(TargetResources[0].id)
  | extend targetType = tostring(TargetResources[0].type)
  | extend keyEvents = TargetResources[0].modifiedProperties
  | mv-expand keyEvents
  | where keyEvents.displayName =~ "KeyDescription"
  | extend new_value_set = parse_json(tostring(keyEvents.newValue))
  | extend old_value_set = parse_json(tostring(keyEvents.oldValue))
  | where old_value_set != "[]"
  | extend diff = set_difference(new_value_set, old_value_set)
  | where isnotempty(diff)
  | parse diff with * "KeyIdentifier=" keyIdentifier:string ",KeyType=" keyType:string ",KeyUsage=" keyUsage:string ",DisplayName=" keyDisplayName:string "]" *
  | where keyUsage == "Verify"  or keyUsage == ""
  | extend UserAgent = iff(AdditionalDetails[0].key == "User-Agent",tostring(AdditionalDetails[0].value),"")
  | extend InitiatingUserOrApp = iff(isnotempty(InitiatedBy.user.userPrincipalName),tostring(InitiatedBy.user.userPrincipalName), tostring(InitiatedBy.app.displayName))
  | extend InitiatingIpAddress = iff(isnotempty(InitiatedBy.user.ipAddress), tostring(InitiatedBy.user.ipAddress), tostring(InitiatedBy.app.ipAddress))
  // The below line is currently commented out but Microsoft Sentinel users can modify this query to show only Application or only Service Principal events in their environment
  //| where targetType =~ "Application" // or targetType =~ "ServicePrincipal"
  | project-away diff, new_value_set, old_value_set
  | project-reorder TimeGenerated, OperationName, InitiatingUserOrApp, InitiatingIpAddress, UserAgent, targetDisplayName, targetId, targetType, keyDisplayName, keyType, keyUsage, keyIdentifier, CorrelationId, TenantId
  | extend timestamp = TimeGenerated, AccountCustomEntity = InitiatingUserOrApp, IPCustomEntity = InitiatingIpAddress  
tags:
- Solorigate
- NOBELIUM
triggerOperator: gt
id: 79566f41-df67-4e10-a703-c38a6213afd8
description: |
  'This will alert when an admin or app owner account adds a new credential to an Application or Service Principal where a verify KeyCredential was already present for the app.
  If a threat actor obtains access to an account with sufficient privileges and adds the alternate authentication material triggering this event, the threat actor can now authenticate as the Application or Service Principal using this credential.
  Additional information on OAuth Credential Grants can be found in RFC 6749 Section 4.4 or https://docs.microsoft.com/azure/active-directory/develop/v2-oauth2-client-creds-grant-flow
  For further information on AuditLogs please see https://docs.microsoft.com/azure/active-directory/reports-monitoring/reference-audit-activities.'  
triggerThreshold: 0
name: New access credential added to Application or Service Principal
relevantTechniques:
- T1550.001
tactics:
- DefenseEvasion
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Azure Active Directory/Analytic Rules/NewAppOrServicePrincipalCredential.yaml

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "workspace": {
      "type": "String"
    }
  },
  "resources": [
    {
      "id": "[concat(resourceId('Microsoft.OperationalInsights/workspaces/providers', parameters('workspace'), 'Microsoft.SecurityInsights'),'/alertRules/79566f41-df67-4e10-a703-c38a6213afd8')]",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/79566f41-df67-4e10-a703-c38a6213afd8')]",
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules",
      "kind": "Scheduled",
      "apiVersion": "2022-11-01",
      "properties": {
        "displayName": "New access credential added to Application or Service Principal",
        "description": "'This will alert when an admin or app owner account adds a new credential to an Application or Service Principal where a verify KeyCredential was already present for the app.\nIf a threat actor obtains access to an account with sufficient privileges and adds the alternate authentication material triggering this event, the threat actor can now authenticate as the Application or Service Principal using this credential.\nAdditional information on OAuth Credential Grants can be found in RFC 6749 Section 4.4 or https://docs.microsoft.com/azure/active-directory/develop/v2-oauth2-client-creds-grant-flow\nFor further information on AuditLogs please see https://docs.microsoft.com/azure/active-directory/reports-monitoring/reference-audit-activities.'\n",
        "severity": "Medium",
        "enabled": true,
        "query": "AuditLogs\n| where OperationName has_any (\"Add service principal\", \"Certificates and secrets management\") // captures \"Add service principal\", \"Add service principal credentials\", and \"Update application - Certificates and secrets management\" events\n| where Result =~ \"success\"\n| mv-expand target = TargetResources\n| where tostring(InitiatedBy.user.userPrincipalName) has \"@\" or tostring(InitiatedBy.app.displayName) has \"@\"\n| extend targetDisplayName = tostring(TargetResources[0].displayName)\n| extend targetId = tostring(TargetResources[0].id)\n| extend targetType = tostring(TargetResources[0].type)\n| extend keyEvents = TargetResources[0].modifiedProperties\n| mv-expand keyEvents\n| where keyEvents.displayName =~ \"KeyDescription\"\n| extend new_value_set = parse_json(tostring(keyEvents.newValue))\n| extend old_value_set = parse_json(tostring(keyEvents.oldValue))\n| where old_value_set != \"[]\"\n| extend diff = set_difference(new_value_set, old_value_set)\n| where isnotempty(diff)\n| parse diff with * \"KeyIdentifier=\" keyIdentifier:string \",KeyType=\" keyType:string \",KeyUsage=\" keyUsage:string \",DisplayName=\" keyDisplayName:string \"]\" *\n| where keyUsage == \"Verify\"  or keyUsage == \"\"\n| extend UserAgent = iff(AdditionalDetails[0].key == \"User-Agent\",tostring(AdditionalDetails[0].value),\"\")\n| extend InitiatingUserOrApp = iff(isnotempty(InitiatedBy.user.userPrincipalName),tostring(InitiatedBy.user.userPrincipalName), tostring(InitiatedBy.app.displayName))\n| extend InitiatingIpAddress = iff(isnotempty(InitiatedBy.user.ipAddress), tostring(InitiatedBy.user.ipAddress), tostring(InitiatedBy.app.ipAddress))\n// The below line is currently commented out but Microsoft Sentinel users can modify this query to show only Application or only Service Principal events in their environment\n//| where targetType =~ \"Application\" // or targetType =~ \"ServicePrincipal\"\n| project-away diff, new_value_set, old_value_set\n| project-reorder TimeGenerated, OperationName, InitiatingUserOrApp, InitiatingIpAddress, UserAgent, targetDisplayName, targetId, targetType, keyDisplayName, keyType, keyUsage, keyIdentifier, CorrelationId, TenantId\n| extend timestamp = TimeGenerated, AccountCustomEntity = InitiatingUserOrApp, IPCustomEntity = InitiatingIpAddress\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "PT1H",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0,
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "DefenseEvasion"
        ],
        "techniques": [
          "T1550.001"
        ],
        "alertRuleTemplateName": "79566f41-df67-4e10-a703-c38a6213afd8",
        "customDetails": null,
        "entityMappings": [
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "identifier": "FullName",
                "columnName": "AccountCustomEntity"
              }
            ]
          },
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "identifier": "Address",
                "columnName": "IPCustomEntity"
              }
            ]
          }
        ],
        "tags": [
          "Solorigate",
          "NOBELIUM"
        ],
        "status": "Available",
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Azure Active Directory/Analytic Rules/NewAppOrServicePrincipalCredential.yaml",
        "templateVersion": "1.1.0"
      }
    }
  ]
}