WDigest downgrade attack | Microsoft Sentinel Analytic Rules

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Id	f6502545-ae3a-4232-a8b0-79d87e5c98d7
Rulename	WDigest downgrade attack
Description	When the WDigest Authentication protocol is enabled, plain text passwords are stored in the Local Security Authority Subsystem Service (LSASS) exposing them to theft. This setting will prevent WDigest from storing credentials in memory. Ref: https://www.stigviewer.com/stig/windows_7/2016-12-19/finding/V-72753
Severity	Medium
Tactics	CredentialAccess
Techniques	T1003
Required data connectors	SecurityEvents WindowsSecurityEvents
Kind	Scheduled
Query frequency	1h
Query period	1h
Trigger threshold	0
Trigger operator	gt
Source Uri	https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Endpoint%20Threat%20Protection%20Essentials/Analytic%20Rules/WDigestDowngradeAttack.yaml
Version	1.0.3
Arm template	f6502545-ae3a-4232-a8b0-79d87e5c98d7.json

KQL

Event
| where EventLog =~ "Microsoft-Windows-Sysmon/Operational" and EventID in (13)
| parse EventData with * 'TargetObject">' TargetObject "<" * 'Details">' Details "<" * 
| where TargetObject=~"HKLM\\System\\CurrentControlSet\\Control\\SecurityProviders\\WDigest\\UseLogonCredential" and Details !="DWORD (0x00000000)"
| summarize StartTimeUtc = min(TimeGenerated), EndTimeUtc = max(TimeGenerated) by EventID, Computer,  TargetObject, Details
| extend HostName = iif(Computer has '.',substring(Computer,0,indexof(Computer,'.')),Computer) , DnsDomain = iif(Computer has '.',substring(Computer,indexof(Computer,'.')+1),'')

YAML

name: WDigest downgrade attack
triggerOperator: gt
query: |
  Event
  | where EventLog =~ "Microsoft-Windows-Sysmon/Operational" and EventID in (13)
  | parse EventData with * 'TargetObject">' TargetObject "<" * 'Details">' Details "<" * 
  | where TargetObject=~"HKLM\\System\\CurrentControlSet\\Control\\SecurityProviders\\WDigest\\UseLogonCredential" and Details !="DWORD (0x00000000)"
  | summarize StartTimeUtc = min(TimeGenerated), EndTimeUtc = max(TimeGenerated) by EventID, Computer,  TargetObject, Details
  | extend HostName = iif(Computer has '.',substring(Computer,0,indexof(Computer,'.')),Computer) , DnsDomain = iif(Computer has '.',substring(Computer,indexof(Computer,'.')+1),'')
queryFrequency: 1h
description: |
  'When the WDigest Authentication protocol is enabled, plain text passwords are stored in the Local Security Authority Subsystem Service (LSASS) exposing them to theft. This setting will prevent WDigest from storing credentials in memory.
  Ref: https://www.stigviewer.com/stig/windows_7/2016-12-19/finding/V-72753'
id: f6502545-ae3a-4232-a8b0-79d87e5c98d7
triggerThreshold: 0
queryPeriod: 1h
version: 1.0.3
kind: Scheduled
status: Available
severity: Medium
requiredDataConnectors:
- connectorId: SecurityEvents
  dataTypes:
  - SecurityEvent
- connectorId: WindowsSecurityEvents
  dataTypes:
  - SecurityEvent
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Endpoint%20Threat%20Protection%20Essentials/Analytic%20Rules/WDigestDowngradeAttack.yaml
relevantTechniques:
- T1003
tactics:
- CredentialAccess
entityMappings:
- fieldMappings:
  - identifier: Key
    columnName: TargetObject
  entityType: RegistryKey
- fieldMappings:
  - identifier: FullName
    columnName: Computer
  - identifier: HostName
    columnName: HostName
  - identifier: DnsDomain
    columnName: DnsDomain
  entityType: Host

ARM

{
  "$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/f6502545-ae3a-4232-a8b0-79d87e5c98d7')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/f6502545-ae3a-4232-a8b0-79d87e5c98d7')]",
      "properties": {
        "alertRuleTemplateName": "f6502545-ae3a-4232-a8b0-79d87e5c98d7",
        "customDetails": null,
        "description": "'When the WDigest Authentication protocol is enabled, plain text passwords are stored in the Local Security Authority Subsystem Service (LSASS) exposing them to theft. This setting will prevent WDigest from storing credentials in memory.\nRef: https://www.stigviewer.com/stig/windows_7/2016-12-19/finding/V-72753'\n",
        "displayName": "WDigest downgrade attack",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "RegistryKey",
            "fieldMappings": [
              {
                "columnName": "TargetObject",
                "identifier": "Key"
              }
            ]
          },
          {
            "entityType": "Host",
            "fieldMappings": [
              {
                "columnName": "Computer",
                "identifier": "FullName"
              },
              {
                "columnName": "HostName",
                "identifier": "HostName"
              },
              {
                "columnName": "DnsDomain",
                "identifier": "DnsDomain"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Endpoint%20Threat%20Protection%20Essentials/Analytic%20Rules/WDigestDowngradeAttack.yaml",
        "query": "Event\n| where EventLog =~ \"Microsoft-Windows-Sysmon/Operational\" and EventID in (13)\n| parse EventData with * 'TargetObject\">' TargetObject \"<\" * 'Details\">' Details \"<\" * \n| where TargetObject=~\"HKLM\\\\System\\\\CurrentControlSet\\\\Control\\\\SecurityProviders\\\\WDigest\\\\UseLogonCredential\" and Details !=\"DWORD (0x00000000)\"\n| summarize StartTimeUtc = min(TimeGenerated), EndTimeUtc = max(TimeGenerated) by EventID, Computer,  TargetObject, Details\n| extend HostName = iif(Computer has '.',substring(Computer,0,indexof(Computer,'.')),Computer) , DnsDomain = iif(Computer has '.',substring(Computer,indexof(Computer,'.')+1),'')\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "PT1H",
        "severity": "Medium",
        "status": "Available",
        "subTechniques": [],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "CredentialAccess"
        ],
        "techniques": [
          "T1003"
        ],
        "templateVersion": "1.0.3",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}