Device Alert Surge

MorphisecAlerts_CL
| where threatMessageArrivalTime >= ago(1h)
| where attackSeverity in ("HIGH", "MEDIUM")
| summarize arg_max(threatMessageArrivalTime, *) by id
| summarize AlertCount = dcount(id) by hostname
| where AlertCount >= 5

suppressionDuration: 5h
name: Device Alert Surge
suppressionEnabled: false
triggerOperator: gt
query: |
  MorphisecAlerts_CL
  | where threatMessageArrivalTime >= ago(1h)
  | where attackSeverity in ("HIGH", "MEDIUM")
  | summarize arg_max(threatMessageArrivalTime, *) by id
  | summarize AlertCount = dcount(id) by hostname
  | where AlertCount >= 5
queryFrequency: 1h
description: |
  'Triggers an incident when a device generates 5 or more Medium or High severity alerts, indicating potential compromise.'
id: 5c8e1f2e-9d6b-4f4a-8f3e-123456789abc
triggerThreshold: 0
queryPeriod: 1h
version: 1.0.0
kind: Scheduled
status: Available
eventGroupingSettings:
  aggregationKind: SingleAlert
severity: High
requiredDataConnectors:
- connectorId: MorphisecCCF
  dataTypes:
  - Morphisec
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Morphisec/Analytic%20Rules/MorphisecDeviceAlertSurge.yaml
incidentConfiguration:
  groupingConfiguration:
    groupByAlertDetails:
    - DisplayName
    lookbackDuration: 1h
    enabled: false
    reopenClosedIncident: false
    matchingMethod: AllEntities
    groupByEntities:
    - Host
  createIncident: true
alertDetailsOverride:
  alertDescriptionFormat: Device {{hostname}} triggered {{AlertCount}} distinct High/Medium alerts within the last hour.
  alertDisplayNameFormat: 'Device alert surge detected: {{hostname}}'
relevantTechniques:
- T1059
- T1204
tactics:
- Execution
- DefenseEvasion
entityMappings:
- fieldMappings:
  - identifier: HostName
    columnName: hostname
  entityType: Host

{
  "$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/5c8e1f2e-9d6b-4f4a-8f3e-123456789abc')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/5c8e1f2e-9d6b-4f4a-8f3e-123456789abc')]",
      "properties": {
        "alertDetailsOverride": {
          "alertDescriptionFormat": "Device {{hostname}} triggered {{AlertCount}} distinct High/Medium alerts within the last hour.",
          "alertDisplayNameFormat": "Device alert surge detected: {{hostname}}"
        },
        "alertRuleTemplateName": "5c8e1f2e-9d6b-4f4a-8f3e-123456789abc",
        "customDetails": null,
        "description": "'Triggers an incident when a device generates 5 or more Medium or High severity alerts, indicating potential compromise.'\n",
        "displayName": "Device Alert Surge",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Host",
            "fieldMappings": [
              {
                "columnName": "hostname",
                "identifier": "HostName"
              }
            ]
          }
        ],
        "eventGroupingSettings": {
          "aggregationKind": "SingleAlert"
        },
        "incidentConfiguration": {
          "createIncident": true,
          "groupingConfiguration": {
            "enabled": false,
            "groupByAlertDetails": [
              "DisplayName"
            ],
            "groupByEntities": [
              "Host"
            ],
            "lookbackDuration": "PT1H",
            "matchingMethod": "AllEntities",
            "reopenClosedIncident": false
          }
        },
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Morphisec/Analytic%20Rules/MorphisecDeviceAlertSurge.yaml",
        "query": "MorphisecAlerts_CL\n| where threatMessageArrivalTime >= ago(1h)\n| where attackSeverity in (\"HIGH\", \"MEDIUM\")\n| summarize arg_max(threatMessageArrivalTime, *) by id\n| summarize AlertCount = dcount(id) by hostname\n| where AlertCount >= 5\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "PT1H",
        "severity": "High",
        "status": "Available",
        "subTechniques": [],
        "suppressionDuration": "PT5H",
        "suppressionEnabled": false,
        "tactics": [
          "DefenseEvasion",
          "Execution"
        ],
        "techniques": [
          "T1059",
          "T1204"
        ],
        "templateVersion": "1.0.0",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}