User account created without expected attributes defined

let threshold = 10;
let default_ad_attributes = dynamic(["LastDirSyncTime", "StsRefreshTokensValidFrom", "Included Updated Properties", "AccountEnabled", "Action Client Name", "SourceAnchor"]);
AuditLogs
| where OperationName =~ "Add user"
| where Result =~ "success"
| extend properties = TargetResources[0].modifiedProperties
| mv-expand properties
| evaluate bag_unpack(properties) : (displayName:string, oldValue: string, newValue: string , TenantId : string, SourceSystem : string, TimeGenerated : datetime, ResourceId : string, OperationName : string, OperationVersion : string, Category : string, ResultType : string, ResultSignature : string, ResultDescription : string, DurationMs : long, CorrelationId : string, Resource : string, ResourceGroup : string, ResourceProvider : string, Identity : string, Level : string, Location : string, AdditionalDetails : dynamic, Id : string, InitiatedBy : dynamic, LoggedByService : string, Result : string, ResultReason : string, TargetResources : dynamic, AADTenantId : string, ActivityDisplayName : string, ActivityDateTime : datetime, AADOperationType : string, Type : string)
| extend displayName = column_ifexists("displayName", "Unknown Value")
| summarize count() by displayName, TenantId
| where displayName !in (default_ad_attributes)
| top threshold by count_ desc
| summarize make_set(displayName) by TenantId
| join kind=inner (AuditLogs
| where Result =~ "success"
| where OperationName =~ "Add user"
| extend CreatingUserPrincipalName = tostring(parse_json(tostring(InitiatedBy.user)).userPrincipalName)
| extend CreatedUserPrincipalName = tostring(TargetResources[0].userPrincipalName)
| extend AccountProperties = TargetResources[0].modifiedProperties
| mv-expand AccountProperties
| extend PropName = tostring(AccountProperties.displayName)) on TenantId
| summarize makeset(PropName) by TimeGenerated, CorrelationId, CreatedUserPrincipalName, CreatingUserPrincipalName, tostring(set_displayName)
| extend missing_props = set_difference(todynamic(set_displayName), set_PropName)
| where array_length(missing_props) > 0
| join kind=innerunique (AuditLogs
| where Result =~ "success"
| where OperationName =~ "Add user"
| extend CreatedUserPrincipalName = tostring(TargetResources[0].userPrincipalName)) on CorrelationId, CreatedUserPrincipalName
| extend ExpectedProperties = set_displayName
| project-away set_displayName, set_PropName

triggerOperator: gt
id: dc99e38c-f4e9-4837-94d7-353ac0b01a77
queryFrequency: 1d
entityMappings:
- entityType: Account
  fieldMappings:
  - columnName: CreatingUserPrincipalName
    identifier: FullName
- entityType: Account
  fieldMappings:
  - columnName: CreatedUserPrincipalName
    identifier: FullName
requiredDataConnectors:
- dataTypes:
  - AuditLogs
  connectorId: AzureActiveDirectory
severity: Low
metadata:
  source:
    kind: Community
  categories:
    domains:
    - Security - Others
  support:
    tier: Community
  author:
    name: Pete Bryan
triggerThreshold: 0
kind: Scheduled
queryPeriod: 1d
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Detections/AuditLogs/Useraccountcreatedwithoutexpectedattributesdefined.yaml
query: |
  let threshold = 10;
  let default_ad_attributes = dynamic(["LastDirSyncTime", "StsRefreshTokensValidFrom", "Included Updated Properties", "AccountEnabled", "Action Client Name", "SourceAnchor"]);
  AuditLogs
  | where OperationName =~ "Add user"
  | where Result =~ "success"
  | extend properties = TargetResources[0].modifiedProperties
  | mv-expand properties
  | evaluate bag_unpack(properties) : (displayName:string, oldValue: string, newValue: string , TenantId : string, SourceSystem : string, TimeGenerated : datetime, ResourceId : string, OperationName : string, OperationVersion : string, Category : string, ResultType : string, ResultSignature : string, ResultDescription : string, DurationMs : long, CorrelationId : string, Resource : string, ResourceGroup : string, ResourceProvider : string, Identity : string, Level : string, Location : string, AdditionalDetails : dynamic, Id : string, InitiatedBy : dynamic, LoggedByService : string, Result : string, ResultReason : string, TargetResources : dynamic, AADTenantId : string, ActivityDisplayName : string, ActivityDateTime : datetime, AADOperationType : string, Type : string)
  | extend displayName = column_ifexists("displayName", "Unknown Value")
  | summarize count() by displayName, TenantId
  | where displayName !in (default_ad_attributes)
  | top threshold by count_ desc
  | summarize make_set(displayName) by TenantId
  | join kind=inner (AuditLogs
  | where Result =~ "success"
  | where OperationName =~ "Add user"
  | extend CreatingUserPrincipalName = tostring(parse_json(tostring(InitiatedBy.user)).userPrincipalName)
  | extend CreatedUserPrincipalName = tostring(TargetResources[0].userPrincipalName)
  | extend AccountProperties = TargetResources[0].modifiedProperties
  | mv-expand AccountProperties
  | extend PropName = tostring(AccountProperties.displayName)) on TenantId
  | summarize makeset(PropName) by TimeGenerated, CorrelationId, CreatedUserPrincipalName, CreatingUserPrincipalName, tostring(set_displayName)
  | extend missing_props = set_difference(todynamic(set_displayName), set_PropName)
  | where array_length(missing_props) > 0
  | join kind=innerunique (AuditLogs
  | where Result =~ "success"
  | where OperationName =~ "Add user"
  | extend CreatedUserPrincipalName = tostring(TargetResources[0].userPrincipalName)) on CorrelationId, CreatedUserPrincipalName
  | extend ExpectedProperties = set_displayName
  | project-away set_displayName, set_PropName  
description: |
  'This query looks for accounts being created that do not have attributes populated that are commonly populated in the tenant.
    Attackers may attempt to add accounts as a means of establishing persistant access to an environment, looking for anomalies in created accounts may help identify illegitimately created accounts.
    Created accounts should be investigated to ensure they were legitimated created.
    Ref: https://docs.microsoft.com/azure/active-directory/fundamentals/security-operations-user-accounts#accounts-not-following-naming-policies'  
name: User account created without expected attributes defined
relevantTechniques:
- T1136.003
tactics:
- Persistence
version: 1.0.3
tags:
- AADSecOpsGuide

{
  "$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/dc99e38c-f4e9-4837-94d7-353ac0b01a77')]",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/dc99e38c-f4e9-4837-94d7-353ac0b01a77')]",
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules",
      "kind": "Scheduled",
      "apiVersion": "2022-11-01",
      "properties": {
        "displayName": "User account created without expected attributes defined",
        "description": "'This query looks for accounts being created that do not have attributes populated that are commonly populated in the tenant.\n  Attackers may attempt to add accounts as a means of establishing persistant access to an environment, looking for anomalies in created accounts may help identify illegitimately created accounts.\n  Created accounts should be investigated to ensure they were legitimated created.\n  Ref: https://docs.microsoft.com/azure/active-directory/fundamentals/security-operations-user-accounts#accounts-not-following-naming-policies'\n",
        "severity": "Low",
        "enabled": true,
        "query": "let threshold = 10;\nlet default_ad_attributes = dynamic([\"LastDirSyncTime\", \"StsRefreshTokensValidFrom\", \"Included Updated Properties\", \"AccountEnabled\", \"Action Client Name\", \"SourceAnchor\"]);\nAuditLogs\n| where OperationName =~ \"Add user\"\n| where Result =~ \"success\"\n| extend properties = TargetResources[0].modifiedProperties\n| mv-expand properties\n| evaluate bag_unpack(properties) : (displayName:string, oldValue: string, newValue: string , TenantId : string, SourceSystem : string, TimeGenerated : datetime, ResourceId : string, OperationName : string, OperationVersion : string, Category : string, ResultType : string, ResultSignature : string, ResultDescription : string, DurationMs : long, CorrelationId : string, Resource : string, ResourceGroup : string, ResourceProvider : string, Identity : string, Level : string, Location : string, AdditionalDetails : dynamic, Id : string, InitiatedBy : dynamic, LoggedByService : string, Result : string, ResultReason : string, TargetResources : dynamic, AADTenantId : string, ActivityDisplayName : string, ActivityDateTime : datetime, AADOperationType : string, Type : string)\n| extend displayName = column_ifexists(\"displayName\", \"Unknown Value\")\n| summarize count() by displayName, TenantId\n| where displayName !in (default_ad_attributes)\n| top threshold by count_ desc\n| summarize make_set(displayName) by TenantId\n| join kind=inner (AuditLogs\n| where Result =~ \"success\"\n| where OperationName =~ \"Add user\"\n| extend CreatingUserPrincipalName = tostring(parse_json(tostring(InitiatedBy.user)).userPrincipalName)\n| extend CreatedUserPrincipalName = tostring(TargetResources[0].userPrincipalName)\n| extend AccountProperties = TargetResources[0].modifiedProperties\n| mv-expand AccountProperties\n| extend PropName = tostring(AccountProperties.displayName)) on TenantId\n| summarize makeset(PropName) by TimeGenerated, CorrelationId, CreatedUserPrincipalName, CreatingUserPrincipalName, tostring(set_displayName)\n| extend missing_props = set_difference(todynamic(set_displayName), set_PropName)\n| where array_length(missing_props) > 0\n| join kind=innerunique (AuditLogs\n| where Result =~ \"success\"\n| where OperationName =~ \"Add user\"\n| extend CreatedUserPrincipalName = tostring(TargetResources[0].userPrincipalName)) on CorrelationId, CreatedUserPrincipalName\n| extend ExpectedProperties = set_displayName\n| project-away set_displayName, set_PropName\n",
        "queryFrequency": "P1D",
        "queryPeriod": "P1D",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0,
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "Persistence"
        ],
        "techniques": [
          "T1136.003"
        ],
        "alertRuleTemplateName": "dc99e38c-f4e9-4837-94d7-353ac0b01a77",
        "customDetails": null,
        "entityMappings": [
          {
            "fieldMappings": [
              {
                "identifier": "FullName",
                "columnName": "CreatingUserPrincipalName"
              }
            ],
            "entityType": "Account"
          },
          {
            "fieldMappings": [
              {
                "identifier": "FullName",
                "columnName": "CreatedUserPrincipalName"
              }
            ],
            "entityType": "Account"
          }
        ],
        "templateVersion": "1.0.3",
        "tags": [
          "AADSecOpsGuide"
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Detections/AuditLogs/Useraccountcreatedwithoutexpectedattributesdefined.yaml"
      }
    }
  ]
}