DDoS attack detected

let TimeWindow   = 90d;    
let HitThreshold = 10;
let MinSeverity  = 2;
let EnableCategoryFilter    = true;
let EnableDescriptionFilter = false;
let EnableActionFilter      = false;
let CategoriesOfInterest = dynamic([
    "Attempted Denial of Service",
    "Denial of Service",
    "Detection of a Denial of Service Attack"
]);
let DescriptionsOfInterest = dynamic([
    "attempted-dos",
    "successful-dos",
    "denial-of-service"
]);
let MatchActions = dynamic(["Deny", "alert"]);
AZFWIdpsSignature
| where TimeGenerated >= ago(TimeWindow)
| where Severity >= MinSeverity
| where (EnableCategoryFilter == false) or (Category has_any (CategoriesOfInterest))
| where (EnableDescriptionFilter == false) or (Description has_any (DescriptionsOfInterest))
| where (EnableActionFilter == false) or (Action in~ (MatchActions))
| summarize
    StartTime   = min(TimeGenerated),
    EndTime     = max(TimeGenerated),
    TotalHits   = count(),
    MaxSeverity = max(Severity),
    Actions     = make_set(Action, 5),
    Signatures  = make_set(SignatureId, 20),
    Description = make_set(substring(tostring(Description), 0, 120), 3)
    by SourceIp, ThreatCategory = Category
| where TotalHits >= HitThreshold
| project
    StartTime,
    EndTime,
    SourceIp,
    ThreatCategory,
    TotalHits,
    MaxSeverity,
    Actions,
    Signatures,
    Description
| order by MaxSeverity desc, TotalHits desc

name: DDoS attack detected
triggerOperator: gt
query: |
  let TimeWindow   = 90d;    
  let HitThreshold = 10;
  let MinSeverity  = 2;
  let EnableCategoryFilter    = true;
  let EnableDescriptionFilter = false;
  let EnableActionFilter      = false;
  let CategoriesOfInterest = dynamic([
      "Attempted Denial of Service",
      "Denial of Service",
      "Detection of a Denial of Service Attack"
  ]);
  let DescriptionsOfInterest = dynamic([
      "attempted-dos",
      "successful-dos",
      "denial-of-service"
  ]);
  let MatchActions = dynamic(["Deny", "alert"]);
  AZFWIdpsSignature
  | where TimeGenerated >= ago(TimeWindow)
  | where Severity >= MinSeverity
  | where (EnableCategoryFilter == false) or (Category has_any (CategoriesOfInterest))
  | where (EnableDescriptionFilter == false) or (Description has_any (DescriptionsOfInterest))
  | where (EnableActionFilter == false) or (Action in~ (MatchActions))
  | summarize
      StartTime   = min(TimeGenerated),
      EndTime     = max(TimeGenerated),
      TotalHits   = count(),
      MaxSeverity = max(Severity),
      Actions     = make_set(Action, 5),
      Signatures  = make_set(SignatureId, 20),
      Description = make_set(substring(tostring(Description), 0, 120), 3)
      by SourceIp, ThreatCategory = Category
  | where TotalHits >= HitThreshold
  | project
      StartTime,
      EndTime,
      SourceIp,
      ThreatCategory,
      TotalHits,
      MaxSeverity,
      Actions,
      Signatures,
      Description
  | order by MaxSeverity desc, TotalHits desc
queryFrequency: 1h
description: |
  Identifies DDoS attack in Azure Firewall IDPS logs.
id: c3ffdbe6-2e62-4984-9e80-933ed90b2f6a
triggerThreshold: 0
queryPeriod: 24h
version: 1.0.1
kind: Scheduled
status: Available
severity: High
requiredDataConnectors:
- connectorId: AzureFirewall
  dataTypes:
  - AZFWIdpsSignature
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Azure%20Firewall/Analytic%20Rules/Azure%20Firewall%20-%20DDoS%20attack%20detected.yaml
relevantTechniques:
- T1498
tactics:
- Impact
entityMappings:
- fieldMappings:
  - identifier: Address
    columnName: SourceIp
  entityType: IP

{
  "$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/c3ffdbe6-2e62-4984-9e80-933ed90b2f6a')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/c3ffdbe6-2e62-4984-9e80-933ed90b2f6a')]",
      "properties": {
        "alertRuleTemplateName": "c3ffdbe6-2e62-4984-9e80-933ed90b2f6a",
        "customDetails": null,
        "description": "Identifies DDoS attack in Azure Firewall IDPS logs.\n",
        "displayName": "DDoS attack detected",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "columnName": "SourceIp",
                "identifier": "Address"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Azure%20Firewall/Analytic%20Rules/Azure%20Firewall%20-%20DDoS%20attack%20detected.yaml",
        "query": "let TimeWindow   = 90d;    \nlet HitThreshold = 10;\nlet MinSeverity  = 2;\nlet EnableCategoryFilter    = true;\nlet EnableDescriptionFilter = false;\nlet EnableActionFilter      = false;\nlet CategoriesOfInterest = dynamic([\n    \"Attempted Denial of Service\",\n    \"Denial of Service\",\n    \"Detection of a Denial of Service Attack\"\n]);\nlet DescriptionsOfInterest = dynamic([\n    \"attempted-dos\",\n    \"successful-dos\",\n    \"denial-of-service\"\n]);\nlet MatchActions = dynamic([\"Deny\", \"alert\"]);\nAZFWIdpsSignature\n| where TimeGenerated >= ago(TimeWindow)\n| where Severity >= MinSeverity\n| where (EnableCategoryFilter == false) or (Category has_any (CategoriesOfInterest))\n| where (EnableDescriptionFilter == false) or (Description has_any (DescriptionsOfInterest))\n| where (EnableActionFilter == false) or (Action in~ (MatchActions))\n| summarize\n    StartTime   = min(TimeGenerated),\n    EndTime     = max(TimeGenerated),\n    TotalHits   = count(),\n    MaxSeverity = max(Severity),\n    Actions     = make_set(Action, 5),\n    Signatures  = make_set(SignatureId, 20),\n    Description = make_set(substring(tostring(Description), 0, 120), 3)\n    by SourceIp, ThreatCategory = Category\n| where TotalHits >= HitThreshold\n| project\n    StartTime,\n    EndTime,\n    SourceIp,\n    ThreatCategory,\n    TotalHits,\n    MaxSeverity,\n    Actions,\n    Signatures,\n    Description\n| order by MaxSeverity desc, TotalHits desc\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "PT24H",
        "severity": "High",
        "status": "Available",
        "subTechniques": [],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "Impact"
        ],
        "techniques": [
          "T1498"
        ],
        "templateVersion": "1.0.1",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}