BTP - Mass user deletion in a sub account

let bulk_delete_threshold = 10;
SAPBTPAuditLog_CL
| where isnotnull(Message.object)
| where Message.object has "scim user" and Message.object has "DELETE"
| mv-expand Attributes = Message.attributes
| where isnotempty(Attributes.old)
| extend DeletedUserName = tostring(parse_json(tostring(Attributes.old)).userName)
| where isnotempty(DeletedUserName)
| summarize
    Start = min(UpdatedOn),
    End = max(UpdatedOn),
    DeletedUsers = make_set(DeletedUserName, 100)
    by UserName, Tenant, SpaceId
| where array_length(DeletedUsers) > bulk_delete_threshold
| project Start, End, UserName, DeletedUsers, Tenant, SpaceId, CloudApp = "SAP BTP"
| extend AccountName = split(UserName, "@")[0], UPNSuffix = split(UserName, "@")[1]

queryPeriod: 1h
id: 6f1e58bd-cd95-4dfb-8883-94207f30929a
relevantTechniques:
- T1531
- T1485
- T1489
- T0813
- T0826
- T0827
triggerOperator: gt
entityMappings:
- fieldMappings:
  - columnName: AccountName
    identifier: Name
  - columnName: UPNSuffix
    identifier: UPNSuffix
  entityType: Account
- fieldMappings:
  - columnName: CloudApp
    identifier: Name
  entityType: CloudApplication
query: |
  let bulk_delete_threshold = 10;
  SAPBTPAuditLog_CL
  | where isnotnull(Message.object)
  | where Message.object has "scim user" and Message.object has "DELETE"
  | mv-expand Attributes = Message.attributes
  | where isnotempty(Attributes.old)
  | extend DeletedUserName = tostring(parse_json(tostring(Attributes.old)).userName)
  | where isnotempty(DeletedUserName)
  | summarize
      Start = min(UpdatedOn),
      End = max(UpdatedOn),
      DeletedUsers = make_set(DeletedUserName, 100)
      by UserName, Tenant, SpaceId
  | where array_length(DeletedUsers) > bulk_delete_threshold
  | project Start, End, UserName, DeletedUsers, Tenant, SpaceId, CloudApp = "SAP BTP"
  | extend AccountName = split(UserName, "@")[0], UPNSuffix = split(UserName, "@")[1]  
kind: Scheduled
triggerThreshold: 0
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/SAP BTP/Analytic Rules/BTP - Mass user deletion in a sub account.yaml
queryFrequency: 1h
requiredDataConnectors:
- dataTypes:
  - SAPBTPAuditLog_CL
  connectorId: SAPBTPAuditEvents
eventGroupingSettings:
  aggregationKind: SingleAlert
name: BTP - Mass user deletion in a sub account
version: 3.0.5
description: Identifies user account deletion activity where the amount of deleted users exceeds a predefined threshold.
tactics:
- Impact
severity: Medium
status: Available

{
  "$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/6f1e58bd-cd95-4dfb-8883-94207f30929a')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/6f1e58bd-cd95-4dfb-8883-94207f30929a')]",
      "properties": {
        "alertRuleTemplateName": "6f1e58bd-cd95-4dfb-8883-94207f30929a",
        "customDetails": null,
        "description": "Identifies user account deletion activity where the amount of deleted users exceeds a predefined threshold.",
        "displayName": "BTP - Mass user deletion in a sub account",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "AccountName",
                "identifier": "Name"
              },
              {
                "columnName": "UPNSuffix",
                "identifier": "UPNSuffix"
              }
            ]
          },
          {
            "entityType": "CloudApplication",
            "fieldMappings": [
              {
                "columnName": "CloudApp",
                "identifier": "Name"
              }
            ]
          }
        ],
        "eventGroupingSettings": {
          "aggregationKind": "SingleAlert"
        },
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/SAP BTP/Analytic Rules/BTP - Mass user deletion in a sub account.yaml",
        "query": "let bulk_delete_threshold = 10;\nSAPBTPAuditLog_CL\n| where isnotnull(Message.object)\n| where Message.object has \"scim user\" and Message.object has \"DELETE\"\n| mv-expand Attributes = Message.attributes\n| where isnotempty(Attributes.old)\n| extend DeletedUserName = tostring(parse_json(tostring(Attributes.old)).userName)\n| where isnotempty(DeletedUserName)\n| summarize\n    Start = min(UpdatedOn),\n    End = max(UpdatedOn),\n    DeletedUsers = make_set(DeletedUserName, 100)\n    by UserName, Tenant, SpaceId\n| where array_length(DeletedUsers) > bulk_delete_threshold\n| project Start, End, UserName, DeletedUsers, Tenant, SpaceId, CloudApp = \"SAP BTP\"\n| extend AccountName = split(UserName, \"@\")[0], UPNSuffix = split(UserName, \"@\")[1]\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "PT1H",
        "severity": "Medium",
        "status": "Available",
        "subTechniques": [],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "Impact"
        ],
        "techniques": [
          "T1485",
          "T1489",
          "T1531"
        ],
        "templateVersion": "3.0.5",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}