CyberArkEPM - Uncommon Windows process started from System folder

let lb_period = 14d;
let q_time = 1h;
let sys_proc = CyberArkEPM
| where TimeGenerated between (ago(lb_period) .. ago(q_time))
| where EventSubType != 'AttackAttempt'
| where ActingProcessName has @'\'
| where ActingProcessName has_any ('System32', 'SysWOW64')
| summarize makeset(ActingProcessFileInternalName);
CyberArkEPM
| where TimeGenerated > ago(q_time)
| where EventSubType != 'AttackAttempt'
| where ActingProcessName has @'\'
| where ActingProcessName has_any ('System32', 'SysWOW64')
| where ActingProcessFileInternalName !in (sys_proc)
| extend AccountCustomEntity = ActorUsername

triggerOperator: gt
queryFrequency: 1h
description: |
    'Detects when uncommon windows proccess is started from System folder.'
version: 1.0.0
kind: Scheduled
triggerThreshold: 0
requiredDataConnectors:
- connectorId: CyberArkEPM
  dataTypes:
  - CyberArkEPM
queryPeriod: 14d
name: CyberArkEPM - Uncommon Windows process started from System folder
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/CyberArkEPM/Analytic Rules/CyberArkEPMNewProcessStartetFromSystem.yaml
id: 16b940d2-aaf8-4eaa-a5e1-05df5f5c3d43
tactics:
- Execution
- DefenseEvasion
relevantTechniques:
- T1204
- T1036
severity: Medium
entityMappings:
- fieldMappings:
  - identifier: Name
    columnName: AccountCustomEntity
  entityType: Account
query: |
  let lb_period = 14d;
  let q_time = 1h;
  let sys_proc = CyberArkEPM
  | where TimeGenerated between (ago(lb_period) .. ago(q_time))
  | where EventSubType != 'AttackAttempt'
  | where ActingProcessName has @'\'
  | where ActingProcessName has_any ('System32', 'SysWOW64')
  | summarize makeset(ActingProcessFileInternalName);
  CyberArkEPM
  | where TimeGenerated > ago(q_time)
  | where EventSubType != 'AttackAttempt'
  | where ActingProcessName has @'\'
  | where ActingProcessName has_any ('System32', 'SysWOW64')
  | where ActingProcessFileInternalName !in (sys_proc)
  | extend AccountCustomEntity = ActorUsername  

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "workspace": {
      "type": "String"
    }
  },
  "resources": [
    {
      "apiVersion": "2023-02-01-preview",
      "id": "[concat(resourceId('Microsoft.OperationalInsights/workspaces/providers', parameters('workspace'), 'Microsoft.SecurityInsights'),'/alertRules/16b940d2-aaf8-4eaa-a5e1-05df5f5c3d43')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/16b940d2-aaf8-4eaa-a5e1-05df5f5c3d43')]",
      "properties": {
        "alertRuleTemplateName": "16b940d2-aaf8-4eaa-a5e1-05df5f5c3d43",
        "customDetails": null,
        "description": "'Detects when uncommon windows proccess is started from System folder.'\n",
        "displayName": "CyberArkEPM - Uncommon Windows process started from System folder",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "AccountCustomEntity",
                "identifier": "Name"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/CyberArkEPM/Analytic Rules/CyberArkEPMNewProcessStartetFromSystem.yaml",
        "query": "let lb_period = 14d;\nlet q_time = 1h;\nlet sys_proc = CyberArkEPM\n| where TimeGenerated between (ago(lb_period) .. ago(q_time))\n| where EventSubType != 'AttackAttempt'\n| where ActingProcessName has @'\\'\n| where ActingProcessName has_any ('System32', 'SysWOW64')\n| summarize makeset(ActingProcessFileInternalName);\nCyberArkEPM\n| where TimeGenerated > ago(q_time)\n| where EventSubType != 'AttackAttempt'\n| where ActingProcessName has @'\\'\n| where ActingProcessName has_any ('System32', 'SysWOW64')\n| where ActingProcessFileInternalName !in (sys_proc)\n| extend AccountCustomEntity = ActorUsername\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "P14D",
        "severity": "Medium",
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "DefenseEvasion",
          "Execution"
        ],
        "techniques": [
          "T1036",
          "T1204"
        ],
        "templateVersion": "1.0.0",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}