Common Event Format CEF via AMA - Critical Severity Detection

let timeframe = 1h;
CrowdStrikeFalconEventStream
| where TimeGenerated > ago(timeframe)
| where EventType == "DetectionSummaryEvent"
| where Severity == "Critical"
| summarize StartTimeUtc = min(TimeGenerated), EndTimeUtc = max(TimeGenerated), Total = count() by DstHostName, SrcIpAddr, DstUserName, Activity, Technique, FileName, FilePath, FileHash, Message
| extend timestamp = StartTimeUtc, AccountCustomEntity = DstUserName, HostCustomEntity = DstHostName, IPCustomEntity = SrcIpAddr, FileHashCustomEntity = FileHash, FileHashAlgo = "MD5"
| project StartTimeUtc, EndTimeUtc, Total, DstHostName, SrcIpAddr, DstUserName, Activity, Technique, FileName, FilePath, FileHash, Message, timestamp, AccountCustomEntity, HostCustomEntity, IPCustomEntity, FileHashCustomEntity, FileHashAlgo

alertDetailsOverride:
  alertDisplayNameFormat: CrowdStrike critical detection on {{DstHostName}}
  alertDescriptionFormat: CrowdStrike reported {{Total}} critical detection(s) on {{DstHostName}} for {{DstUserName}}.
entityMappings:
- fieldMappings:
  - identifier: FullName
    columnName: AccountCustomEntity
  entityType: Account
- fieldMappings:
  - identifier: FullName
    columnName: HostCustomEntity
  entityType: Host
- fieldMappings:
  - identifier: Address
    columnName: IPCustomEntity
  entityType: IP
- fieldMappings:
  - identifier: Algorithm
    columnName: FileHashAlgo
  - identifier: Value
    columnName: FileHashCustomEntity
  entityType: FileHash
id: f7d298b2-726c-42a5-bbac-0d7f9950f527
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/CrowdStrike%20Falcon%20Endpoint%20Protection/Analytic%20Rules/CriticalSeverityDetection.yaml
triggerOperator: gt
tactics:
- Execution
- Impact
kind: Scheduled
requiredDataConnectors:
- dataTypes:
  - CommonSecurityLog
  connectorId: CefAma
queryPeriod: 1h
severity: High
relevantTechniques:
- T1204.002
- T1499
triggerThreshold: 0
version: 1.0.6
customDetails:
  DetectionUser: DstUserName
  DetectionSourceIp: SrcIpAddr
  DetectionFilePath: FilePath
  DetectionTechnique: Technique
  DetectionHost: DstHostName
  DetectionActivity: Activity
  DetectionMessage: Message
  DetectionFileName: FileName
  DetectionCount: Total
name: Common Event Format (CEF) via AMA - Critical Severity Detection
status: Available
query: |
  let timeframe = 1h;
  CrowdStrikeFalconEventStream
  | where TimeGenerated > ago(timeframe)
  | where EventType == "DetectionSummaryEvent"
  | where Severity == "Critical"
  | summarize StartTimeUtc = min(TimeGenerated), EndTimeUtc = max(TimeGenerated), Total = count() by DstHostName, SrcIpAddr, DstUserName, Activity, Technique, FileName, FilePath, FileHash, Message
  | extend timestamp = StartTimeUtc, AccountCustomEntity = DstUserName, HostCustomEntity = DstHostName, IPCustomEntity = SrcIpAddr, FileHashCustomEntity = FileHash, FileHashAlgo = "MD5"
  | project StartTimeUtc, EndTimeUtc, Total, DstHostName, SrcIpAddr, DstUserName, Activity, Technique, FileName, FilePath, FileHash, Message, timestamp, AccountCustomEntity, HostCustomEntity, IPCustomEntity, FileHashCustomEntity, FileHashAlgo
description: |
  'Creates an incident when a CrowdStrike Falcon sensor detection is triggered with Critical severity. The rule queries CrowdStrikeFalconEventStream for DetectionSummaryEvent records where Severity is Critical, summarizes detections by host, source IP, user, activity, technique, file details, hash, and message, and raises an incident for each matching result.'
queryFrequency: 1h

{
  "$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/f7d298b2-726c-42a5-bbac-0d7f9950f527')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/f7d298b2-726c-42a5-bbac-0d7f9950f527')]",
      "properties": {
        "alertDetailsOverride": {
          "alertDescriptionFormat": "CrowdStrike reported {{Total}} critical detection(s) on {{DstHostName}} for {{DstUserName}}.",
          "alertDisplayNameFormat": "CrowdStrike critical detection on {{DstHostName}}"
        },
        "alertRuleTemplateName": "f7d298b2-726c-42a5-bbac-0d7f9950f527",
        "customDetails": {
          "DetectionActivity": "Activity",
          "DetectionCount": "Total",
          "DetectionFileName": "FileName",
          "DetectionFilePath": "FilePath",
          "DetectionHost": "DstHostName",
          "DetectionMessage": "Message",
          "DetectionSourceIp": "SrcIpAddr",
          "DetectionTechnique": "Technique",
          "DetectionUser": "DstUserName"
        },
        "description": "'Creates an incident when a CrowdStrike Falcon sensor detection is triggered with Critical severity. The rule queries CrowdStrikeFalconEventStream for DetectionSummaryEvent records where Severity is Critical, summarizes detections by host, source IP, user, activity, technique, file details, hash, and message, and raises an incident for each matching result.'\n",
        "displayName": "Common Event Format (CEF) via AMA - Critical Severity Detection",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "AccountCustomEntity",
                "identifier": "FullName"
              }
            ]
          },
          {
            "entityType": "Host",
            "fieldMappings": [
              {
                "columnName": "HostCustomEntity",
                "identifier": "FullName"
              }
            ]
          },
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "columnName": "IPCustomEntity",
                "identifier": "Address"
              }
            ]
          },
          {
            "entityType": "FileHash",
            "fieldMappings": [
              {
                "columnName": "FileHashAlgo",
                "identifier": "Algorithm"
              },
              {
                "columnName": "FileHashCustomEntity",
                "identifier": "Value"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/CrowdStrike%20Falcon%20Endpoint%20Protection/Analytic%20Rules/CriticalSeverityDetection.yaml",
        "query": "let timeframe = 1h;\nCrowdStrikeFalconEventStream\n| where TimeGenerated > ago(timeframe)\n| where EventType == \"DetectionSummaryEvent\"\n| where Severity == \"Critical\"\n| summarize StartTimeUtc = min(TimeGenerated), EndTimeUtc = max(TimeGenerated), Total = count() by DstHostName, SrcIpAddr, DstUserName, Activity, Technique, FileName, FilePath, FileHash, Message\n| extend timestamp = StartTimeUtc, AccountCustomEntity = DstUserName, HostCustomEntity = DstHostName, IPCustomEntity = SrcIpAddr, FileHashCustomEntity = FileHash, FileHashAlgo = \"MD5\"\n| project StartTimeUtc, EndTimeUtc, Total, DstHostName, SrcIpAddr, DstUserName, Activity, Technique, FileName, FilePath, FileHash, Message, timestamp, AccountCustomEntity, HostCustomEntity, IPCustomEntity, FileHashCustomEntity, FileHashAlgo\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "PT1H",
        "severity": "High",
        "status": "Available",
        "subTechniques": [
          "T1204.002"
        ],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "Execution",
          "Impact"
        ],
        "techniques": [
          "T1204",
          "T1499"
        ],
        "templateVersion": "1.0.6",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}