[Deprecated] - MSHTML vulnerability CVE-2021-40444 attack

( union isfuzzy=true
(SecurityEvent
| where EventID==4688
| where isnotempty(CommandLine)
| extend FileName = Process, ProcessCommandLine = CommandLine
| where (FileName in~('control.exe','rundll32.exe') and ProcessCommandLine has '.cpl:')
  or ProcessCommandLine matches regex @'\".[a-zA-Z]{2,4}:\.\.\/\.\.'
| extend timestamp = TimeGenerated, AccountCustomEntity = Account, HostCustomEntity = Computer
),
(DeviceProcessEvents
| where (FileName in~('control.exe','rundll32.exe') and ProcessCommandLine has '.cpl:')
or ProcessCommandLine matches regex @'\".[a-zA-Z]{2,4}:\.\.\/\.\.'
| extend timestamp = TimeGenerated, AccountCustomEntity = InitiatingProcessAccountUpn, HostCustomEntity = DeviceName
),
(Event
| where Source == "Microsoft-Windows-Sysmon"
| where EventID == 1 
| extend EventData = parse_xml(EventData).DataItem.EventData.Data
| mv-expand bagexpansion=array EventData
| evaluate bag_unpack(EventData)
| extend Key = tostring(column_ifexists('@Name', "")), Value = column_ifexists('#text', "")
| evaluate pivot(Key, any(Value), TimeGenerated, Source, EventLog, Computer, EventLevel, EventLevelName, UserName, RenderedDescription, MG, ManagementGroupName, Type, _ResourceId)
| extend Image = column_ifexists("Image", ""), ProcessCommandLine = column_ifexists("CommandLine", "")
| extend FileName = split(Image, '\\', -1)[-1]
| where (FileName in~('control.exe','rundll32.exe') and ProcessCommandLine has '.cpl:')
  or ProcessCommandLine matches regex @'\".[a-zA-Z]{2,4}:\.\.\/\.\.'
| extend timestamp = TimeGenerated, AccountCustomEntity = UserName, HostCustomEntity = Computer
)
)

relevantTechniques:
- T1203
name: '[Deprecated] - MSHTML vulnerability CVE-2021-40444 attack'
requiredDataConnectors:
- dataTypes:
  - SecurityEvent
  connectorId: SecurityEvents
- dataTypes:
  - DeviceProcessEvents
  connectorId: MicrosoftThreatProtection
entityMappings:
- fieldMappings:
  - identifier: FullName
    columnName: AccountCustomEntity
  entityType: Account
- fieldMappings:
  - identifier: FullName
    columnName: HostCustomEntity
  entityType: Host
triggerThreshold: 0
id: 972c89fa-c969-4d12-932f-04d55d145299
tactics:
- Execution
version: 2.0.0
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Legacy IOC based Threat Protection/Deprecated Analytic Rules/MSHTMLVuln.yaml
queryPeriod: 1h
kind: Scheduled
tags:
- CVE-2021-40444
- DEV-0413
queryFrequency: 1h
severity: High
status: Available
description: |
    'This query has been deprecated as the associated IoCs (Indicators of Compromise) are outdated and no longer relevant. To ensure effective threat detection, it is recommended to implement Microsoft's Threat Intelligence solution, which enables matching your log data with the most up-to-date IoCs generated by Microsoft. This solution can be installed from the Microsoft Sentinel Content Hub if not currently deployed. More details on the Content Hub can be found here: https://learn.microsoft.com/azure/sentinel/sentinel-solutions-deploy'
query: |
  ( union isfuzzy=true
  (SecurityEvent
  | where EventID==4688
  | where isnotempty(CommandLine)
  | extend FileName = Process, ProcessCommandLine = CommandLine
  | where (FileName in~('control.exe','rundll32.exe') and ProcessCommandLine has '.cpl:')
    or ProcessCommandLine matches regex @'\".[a-zA-Z]{2,4}:\.\.\/\.\.'
  | extend timestamp = TimeGenerated, AccountCustomEntity = Account, HostCustomEntity = Computer
  ),
  (DeviceProcessEvents
  | where (FileName in~('control.exe','rundll32.exe') and ProcessCommandLine has '.cpl:')
  or ProcessCommandLine matches regex @'\".[a-zA-Z]{2,4}:\.\.\/\.\.'
  | extend timestamp = TimeGenerated, AccountCustomEntity = InitiatingProcessAccountUpn, HostCustomEntity = DeviceName
  ),
  (Event
  | where Source == "Microsoft-Windows-Sysmon"
  | where EventID == 1 
  | extend EventData = parse_xml(EventData).DataItem.EventData.Data
  | mv-expand bagexpansion=array EventData
  | evaluate bag_unpack(EventData)
  | extend Key = tostring(column_ifexists('@Name', "")), Value = column_ifexists('#text', "")
  | evaluate pivot(Key, any(Value), TimeGenerated, Source, EventLog, Computer, EventLevel, EventLevelName, UserName, RenderedDescription, MG, ManagementGroupName, Type, _ResourceId)
  | extend Image = column_ifexists("Image", ""), ProcessCommandLine = column_ifexists("CommandLine", "")
  | extend FileName = split(Image, '\\', -1)[-1]
  | where (FileName in~('control.exe','rundll32.exe') and ProcessCommandLine has '.cpl:')
    or ProcessCommandLine matches regex @'\".[a-zA-Z]{2,4}:\.\.\/\.\.'
  | extend timestamp = TimeGenerated, AccountCustomEntity = UserName, HostCustomEntity = Computer
  )
  )  
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/972c89fa-c969-4d12-932f-04d55d145299')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/972c89fa-c969-4d12-932f-04d55d145299')]",
      "properties": {
        "alertRuleTemplateName": "972c89fa-c969-4d12-932f-04d55d145299",
        "customDetails": null,
        "description": "'This query has been deprecated as the associated IoCs (Indicators of Compromise) are outdated and no longer relevant. To ensure effective threat detection, it is recommended to implement Microsoft's Threat Intelligence solution, which enables matching your log data with the most up-to-date IoCs generated by Microsoft. This solution can be installed from the Microsoft Sentinel Content Hub if not currently deployed. More details on the Content Hub can be found here: https://learn.microsoft.com/azure/sentinel/sentinel-solutions-deploy'\n",
        "displayName": "[Deprecated] - MSHTML vulnerability CVE-2021-40444 attack",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "AccountCustomEntity",
                "identifier": "FullName"
              }
            ]
          },
          {
            "entityType": "Host",
            "fieldMappings": [
              {
                "columnName": "HostCustomEntity",
                "identifier": "FullName"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Legacy IOC based Threat Protection/Deprecated Analytic Rules/MSHTMLVuln.yaml",
        "query": "( union isfuzzy=true\n(SecurityEvent\n| where EventID==4688\n| where isnotempty(CommandLine)\n| extend FileName = Process, ProcessCommandLine = CommandLine\n| where (FileName in~('control.exe','rundll32.exe') and ProcessCommandLine has '.cpl:')\n  or ProcessCommandLine matches regex @'\\\".[a-zA-Z]{2,4}:\\.\\.\\/\\.\\.'\n| extend timestamp = TimeGenerated, AccountCustomEntity = Account, HostCustomEntity = Computer\n),\n(DeviceProcessEvents\n| where (FileName in~('control.exe','rundll32.exe') and ProcessCommandLine has '.cpl:')\nor ProcessCommandLine matches regex @'\\\".[a-zA-Z]{2,4}:\\.\\.\\/\\.\\.'\n| extend timestamp = TimeGenerated, AccountCustomEntity = InitiatingProcessAccountUpn, HostCustomEntity = DeviceName\n),\n(Event\n| where Source == \"Microsoft-Windows-Sysmon\"\n| where EventID == 1 \n| extend EventData = parse_xml(EventData).DataItem.EventData.Data\n| mv-expand bagexpansion=array EventData\n| evaluate bag_unpack(EventData)\n| extend Key = tostring(column_ifexists('@Name', \"\")), Value = column_ifexists('#text', \"\")\n| evaluate pivot(Key, any(Value), TimeGenerated, Source, EventLog, Computer, EventLevel, EventLevelName, UserName, RenderedDescription, MG, ManagementGroupName, Type, _ResourceId)\n| extend Image = column_ifexists(\"Image\", \"\"), ProcessCommandLine = column_ifexists(\"CommandLine\", \"\")\n| extend FileName = split(Image, '\\\\', -1)[-1]\n| where (FileName in~('control.exe','rundll32.exe') and ProcessCommandLine has '.cpl:')\n  or ProcessCommandLine matches regex @'\\\".[a-zA-Z]{2,4}:\\.\\.\\/\\.\\.'\n| extend timestamp = TimeGenerated, AccountCustomEntity = UserName, HostCustomEntity = Computer\n)\n)\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "PT1H",
        "severity": "High",
        "status": "Available",
        "subTechniques": [],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "Execution"
        ],
        "tags": [
          "CVE-2021-40444",
          "DEV-0413"
        ],
        "techniques": [
          "T1203"
        ],
        "templateVersion": "2.0.0",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}