NRT New access credential added to Application or Service Principal

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Id	e42e889a-caaf-4dbb-aec6-371b37d64298
Rulename	NRT 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. 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.
Severity	Medium
Tactics	DefenseEvasion
Techniques	T1550.001
Required data connectors	AzureActiveDirectory
Kind	NRT
Source Uri	https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Azure Active Directory/Analytic Rules/NRT_NewAppOrServicePrincipalCredential.yaml
Version	1.0.2
Arm template	e42e889a-caaf-4dbb-aec6-371b37d64298.json

KQL

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"
| where tostring(InitiatedBy.user.userPrincipalName) has "@" or tostring(InitiatedBy.app.displayName) has "@"
| mv-apply TargetResource = TargetResources on 
  (
      where TargetResource.type =~ "Application"
      | extend targetDisplayName = tostring(TargetResource.displayName),
               targetId = tostring(TargetResource.id),
               targetType = tostring(TargetResource.type),
               keyEvents = TargetResource.modifiedProperties
  )
| mv-apply Property = keyEvents on 
  (
      where Property.displayName =~ "KeyDescription"
      | extend new_value_set = parse_json(tostring(Property.newValue)),
               old_value_set = parse_json(tostring(Property.oldValue))
  )
| where old_value_set != "[]"
| extend diff = set_difference(new_value_set, old_value_set)
| where diff != "[]"
| parse diff with * "KeyIdentifier=" keyIdentifier:string ",KeyType=" keyType:string ",KeyUsage=" keyUsage:string ",DisplayName=" keyDisplayName:string "]" *
| where keyUsage =~ "Verify"
| mv-apply AdditionalDetail = AdditionalDetails on 
  (
      where AdditionalDetail.key =~ "User-Agent"
      | extend UserAgent = tostring(AdditionalDetail.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, Name = tostring(split(InitiatingUserOrApp,'@',0)[0]), UPNSuffix = tostring(split(InitiatingUserOrApp,'@',1)[0])

YAML

severity: Medium
relevantTechniques:
- T1550.001
tactics:
- DefenseEvasion
kind: NRT
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"
  | where tostring(InitiatedBy.user.userPrincipalName) has "@" or tostring(InitiatedBy.app.displayName) has "@"
  | mv-apply TargetResource = TargetResources on 
    (
        where TargetResource.type =~ "Application"
        | extend targetDisplayName = tostring(TargetResource.displayName),
                 targetId = tostring(TargetResource.id),
                 targetType = tostring(TargetResource.type),
                 keyEvents = TargetResource.modifiedProperties
    )
  | mv-apply Property = keyEvents on 
    (
        where Property.displayName =~ "KeyDescription"
        | extend new_value_set = parse_json(tostring(Property.newValue)),
                 old_value_set = parse_json(tostring(Property.oldValue))
    )
  | where old_value_set != "[]"
  | extend diff = set_difference(new_value_set, old_value_set)
  | where diff != "[]"
  | parse diff with * "KeyIdentifier=" keyIdentifier:string ",KeyType=" keyType:string ",KeyUsage=" keyUsage:string ",DisplayName=" keyDisplayName:string "]" *
  | where keyUsage =~ "Verify"
  | mv-apply AdditionalDetail = AdditionalDetails on 
    (
        where AdditionalDetail.key =~ "User-Agent"
        | extend UserAgent = tostring(AdditionalDetail.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, Name = tostring(split(InitiatingUserOrApp,'@',0)[0]), UPNSuffix = tostring(split(InitiatingUserOrApp,'@',1)[0])  
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Azure Active Directory/Analytic Rules/NRT_NewAppOrServicePrincipalCredential.yaml
status: Available
version: 1.0.2
tags:
- Solorigate
- NOBELIUM
name: NRT New access credential added to Application or Service Principal
requiredDataConnectors:
- dataTypes:
  - AuditLogs
  connectorId: AzureActiveDirectory
entityMappings:
- entityType: Account
  fieldMappings:
  - identifier: Name
    columnName: Name
  - identifier: UPNSuffix
    columnName: UPNSuffix
- entityType: IP
  fieldMappings:
  - identifier: Address
    columnName: InitiatingIpAddress
id: e42e889a-caaf-4dbb-aec6-371b37d64298
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.'

ARM

{
  "$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/e42e889a-caaf-4dbb-aec6-371b37d64298')]",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/e42e889a-caaf-4dbb-aec6-371b37d64298')]",
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules",
      "kind": "NRT",
      "apiVersion": "2022-11-01-preview",
      "properties": {
        "displayName": "NRT 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| where tostring(InitiatedBy.user.userPrincipalName) has \"@\" or tostring(InitiatedBy.app.displayName) has \"@\"\n| mv-apply TargetResource = TargetResources on \n  (\n      where TargetResource.type =~ \"Application\"\n      | extend targetDisplayName = tostring(TargetResource.displayName),\n               targetId = tostring(TargetResource.id),\n               targetType = tostring(TargetResource.type),\n               keyEvents = TargetResource.modifiedProperties\n  )\n| mv-apply Property = keyEvents on \n  (\n      where Property.displayName =~ \"KeyDescription\"\n      | extend new_value_set = parse_json(tostring(Property.newValue)),\n               old_value_set = parse_json(tostring(Property.oldValue))\n  )\n| where old_value_set != \"[]\"\n| extend diff = set_difference(new_value_set, old_value_set)\n| where diff != \"[]\"\n| parse diff with * \"KeyIdentifier=\" keyIdentifier:string \",KeyType=\" keyType:string \",KeyUsage=\" keyUsage:string \",DisplayName=\" keyDisplayName:string \"]\" *\n| where keyUsage =~ \"Verify\"\n| mv-apply AdditionalDetail = AdditionalDetails on \n  (\n      where AdditionalDetail.key =~ \"User-Agent\"\n      | extend UserAgent = tostring(AdditionalDetail.value)\n  )\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, Name = tostring(split(InitiatingUserOrApp,'@',0)[0]), UPNSuffix = tostring(split(InitiatingUserOrApp,'@',1)[0])\n",
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "DefenseEvasion"
        ],
        "techniques": [
          "T1550.001"
        ],
        "alertRuleTemplateName": "e42e889a-caaf-4dbb-aec6-371b37d64298",
        "customDetails": null,
        "entityMappings": [
          {
            "fieldMappings": [
              {
                "columnName": "Name",
                "identifier": "Name"
              },
              {
                "columnName": "UPNSuffix",
                "identifier": "UPNSuffix"
              }
            ],
            "entityType": "Account"
          },
          {
            "fieldMappings": [
              {
                "columnName": "InitiatingIpAddress",
                "identifier": "Address"
              }
            ],
            "entityType": "IP"
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Azure Active Directory/Analytic Rules/NRT_NewAppOrServicePrincipalCredential.yaml",
        "status": "Available",
        "templateVersion": "1.0.2",
        "tags": [
          "Solorigate",
          "NOBELIUM"
        ]
      }
    }
  ]
}