[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
)
)

tactics:
- Execution
status: Available
requiredDataConnectors:
- connectorId: SecurityEvents
  dataTypes:
  - SecurityEvent
- connectorId: MicrosoftThreatProtection
  dataTypes:
  - DeviceProcessEvents
name: '[Deprecated] - MSHTML vulnerability CVE-2021-40444 attack'
triggerThreshold: 0
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
  )
  )
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Legacy%20IOC%20based%20Threat%20Protection/Deprecated%20Analytic%20Rules/MSHTMLVuln.yaml
tags:
- CVE-2021-40444
- DEV-0413
entityMappings:
- fieldMappings:
  - columnName: AccountCustomEntity
    identifier: FullName
  entityType: Account
- fieldMappings:
  - columnName: HostCustomEntity
    identifier: FullName
  entityType: Host
kind: Scheduled
queryPeriod: 1h
triggerOperator: gt
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'
queryFrequency: 1h
severity: High
relevantTechniques:
- T1203
id: 972c89fa-c969-4d12-932f-04d55d145299
version: 2.0.0

{
  "$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%20IOC%20based%20Threat%20Protection/Deprecated%20Analytic%20Rules/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"
    }
  ]
}