BloodHound Enterprise - Number of Tier Zero assets increase

BloodHoundEnterprise
| where data_type == "posture"
| where created_at > ago (7d)
| summarize min_tier_zero = min(tier_zero_count), max_tier_zero = arg_max(created_at, current_tier_zero = tier_zero_count) by domain_name
| extend percent_difference = ((current_tier_zero - min_tier_zero) / min_tier_zero) * 100
| where percent_difference > 5

relevantTechniques: []
name: BloodHound Enterprise - Number of Tier Zero assets increase
requiredDataConnectors:
- dataTypes:
  - BloodHoundEnterprise
  connectorId: BloodHoundEnterprise
entityMappings:
- fieldMappings:
  - identifier: DomainName
    displayName: domain_name
  entityType: DNS
triggerThreshold: 0
id: 13424be6-aed7-448b-afe5-c03d8b29b4fe
tactics: []
version: 1.0.1
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/BloodHound Enterprise/Analytic Rules/BloodHoundEnterpriseTierZeroAssets.yaml
queryPeriod: 7d
kind: Scheduled
queryFrequency: 7d
severity: Medium
status: Available
description: |
    'The number of Tier Zero assets has increased by more than 5% over the past 7 days.'
query: |
  BloodHoundEnterprise
  | where data_type == "posture"
  | where created_at > ago (7d)
  | summarize min_tier_zero = min(tier_zero_count), max_tier_zero = arg_max(created_at, current_tier_zero = tier_zero_count) by domain_name
  | extend percent_difference = ((current_tier_zero - min_tier_zero) / min_tier_zero) * 100
  | where percent_difference > 5  
triggerOperator: gt

{
  "$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/13424be6-aed7-448b-afe5-c03d8b29b4fe')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/13424be6-aed7-448b-afe5-c03d8b29b4fe')]",
      "properties": {
        "alertRuleTemplateName": "13424be6-aed7-448b-afe5-c03d8b29b4fe",
        "customDetails": null,
        "description": "'The number of Tier Zero assets has increased by more than 5% over the past 7 days.'\n",
        "displayName": "BloodHound Enterprise - Number of Tier Zero assets increase",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "DNS",
            "fieldMappings": [
              {
                "displayName": "domain_name",
                "identifier": "DomainName"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/BloodHound Enterprise/Analytic Rules/BloodHoundEnterpriseTierZeroAssets.yaml",
        "query": "BloodHoundEnterprise\n| where data_type == \"posture\"\n| where created_at > ago (7d)\n| summarize min_tier_zero = min(tier_zero_count), max_tier_zero = arg_max(created_at, current_tier_zero = tier_zero_count) by domain_name\n| extend percent_difference = ((current_tier_zero - min_tier_zero) / min_tier_zero) * 100\n| where percent_difference > 5\n",
        "queryFrequency": "P7D",
        "queryPeriod": "P7D",
        "severity": "Medium",
        "status": "Available",
        "subTechniques": [],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [],
        "techniques": [],
        "templateVersion": "1.0.1",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}