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

queryFrequency: 1h
queryPeriod: 1h
requiredDataConnectors:
- connectorId: CefAma
  dataTypes:
  - CommonSecurityLog
alertDetailsOverride:
  alertDescriptionFormat: CrowdStrike reported {{Total}} critical detection(s) on {{DstHostName}} for {{DstUserName}}.
  alertDisplayNameFormat: CrowdStrike critical detection on {{DstHostName}}
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
triggerOperator: gt
version: 1.0.6
name: Common Event Format (CEF) via AMA - Critical Severity Detection
relevantTechniques:
- T1204.002
- T1499
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
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.'
triggerThreshold: 0
status: Available
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/CrowdStrike%20Falcon%20Endpoint%20Protection/Analytic%20Rules/CriticalSeverityDetection.yaml
severity: High
customDetails:
  DetectionFilePath: FilePath
  DetectionFileName: FileName
  DetectionActivity: Activity
  DetectionSourceIp: SrcIpAddr
  DetectionUser: DstUserName
  DetectionCount: Total
  DetectionHost: DstHostName
  DetectionTechnique: Technique
  DetectionMessage: Message
id: f7d298b2-726c-42a5-bbac-0d7f9950f527
kind: Scheduled
tactics:
- Execution
- Impact

{
  "$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"
    }
  ]
}