Trusted Developer Utilities Proxy Execution

let Timeframe = 1h;
DeviceProcessEvents
| where Timestamp > ago(Timeframe)
| where (FileName has_any ("msbuild.exe", "msxsl.exe")
or (FileName has_any ("vbc.exe","csc.exe","jsc.exe") and ProcessCommandLine has_any ("/exe","/dll","/pe64","-exe","-dll","-pe64"))
or (FileName == ("ilsasm.exe") and ProcessCommandLine has_any ("out","target","t:","reference","r:")))
// Filter initations by Visual Studio since this is expected behavior.
  and not(FolderPath startswith "C:\\Program Files (x86)\\Microsoft Visual Studio" 
  or InitiatingProcessFolderPath startswith "C:\\Program Files (x86)\\Microsoft Visual Studio" 
  and (InitiatingProcessFileName == "devenv.exe" or InitiatingProcessFileName == "WDExpress.exe"))

relevantTechniques:
- T1127
name: Trusted Developer Utilities Proxy Execution
requiredDataConnectors:
- dataTypes:
  - DeviceProcessEvents
  connectorId: MicrosoftThreatProtection
entityMappings:
- fieldMappings:
  - identifier: FullName
    columnName: DeviceName
  entityType: Host
- fieldMappings:
  - identifier: Sid
    columnName: AccountSid
  - identifier: Name
    columnName: AccountName
  - identifier: NTDomain
    columnName: AccountDomain
  entityType: Account
- fieldMappings:
  - identifier: CommandLine
    columnName: ProcessCommandLine
  entityType: Process
triggerThreshold: 0
id: 5c2bb446-926f-4160-a233-21e335c2c290
tactics:
- DefenseEvasion
version: 1.0.0
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/FalconFriday/Analytic Rules/TrustedDeveloperUtilitiesProxyExecution.yaml
queryPeriod: 1h
kind: Scheduled
queryFrequency: 1h
severity: Medium
status: Available
description: |
    This detection looks at process executions - in some cases with specific command line attributes to filter a lot of common noise.
query: |
  let Timeframe = 1h;
  DeviceProcessEvents
  | where Timestamp > ago(Timeframe)
  | where (FileName has_any ("msbuild.exe", "msxsl.exe")
  or (FileName has_any ("vbc.exe","csc.exe","jsc.exe") and ProcessCommandLine has_any ("/exe","/dll","/pe64","-exe","-dll","-pe64"))
  or (FileName == ("ilsasm.exe") and ProcessCommandLine has_any ("out","target","t:","reference","r:")))
  // Filter initations by Visual Studio since this is expected behavior.
    and not(FolderPath startswith "C:\\Program Files (x86)\\Microsoft Visual Studio" 
    or InitiatingProcessFolderPath startswith "C:\\Program Files (x86)\\Microsoft Visual Studio" 
    and (InitiatingProcessFileName == "devenv.exe" or InitiatingProcessFileName == "WDExpress.exe"))  
triggerOperator: gt

{
  "$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/5c2bb446-926f-4160-a233-21e335c2c290')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/5c2bb446-926f-4160-a233-21e335c2c290')]",
      "properties": {
        "alertRuleTemplateName": "5c2bb446-926f-4160-a233-21e335c2c290",
        "customDetails": null,
        "description": "This detection looks at process executions - in some cases with specific command line attributes to filter a lot of common noise.\n",
        "displayName": "Trusted Developer Utilities Proxy Execution",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Host",
            "fieldMappings": [
              {
                "columnName": "DeviceName",
                "identifier": "FullName"
              }
            ]
          },
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "AccountSid",
                "identifier": "Sid"
              },
              {
                "columnName": "AccountName",
                "identifier": "Name"
              },
              {
                "columnName": "AccountDomain",
                "identifier": "NTDomain"
              }
            ]
          },
          {
            "entityType": "Process",
            "fieldMappings": [
              {
                "columnName": "ProcessCommandLine",
                "identifier": "CommandLine"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/FalconFriday/Analytic Rules/TrustedDeveloperUtilitiesProxyExecution.yaml",
        "query": "let Timeframe = 1h;\nDeviceProcessEvents\n| where Timestamp > ago(Timeframe)\n| where (FileName has_any (\"msbuild.exe\", \"msxsl.exe\")\nor (FileName has_any (\"vbc.exe\",\"csc.exe\",\"jsc.exe\") and ProcessCommandLine has_any (\"/exe\",\"/dll\",\"/pe64\",\"-exe\",\"-dll\",\"-pe64\"))\nor (FileName == (\"ilsasm.exe\") and ProcessCommandLine has_any (\"out\",\"target\",\"t:\",\"reference\",\"r:\")))\n// Filter initations by Visual Studio since this is expected behavior.\n  and not(FolderPath startswith \"C:\\\\Program Files (x86)\\\\Microsoft Visual Studio\" \n  or InitiatingProcessFolderPath startswith \"C:\\\\Program Files (x86)\\\\Microsoft Visual Studio\" \n  and (InitiatingProcessFileName == \"devenv.exe\" or InitiatingProcessFileName == \"WDExpress.exe\"))\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "PT1H",
        "severity": "Medium",
        "status": "Available",
        "subTechniques": [],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "DefenseEvasion"
        ],
        "techniques": [
          "T1127"
        ],
        "templateVersion": "1.0.0",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}