WDigest downgrade attack

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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 Threat Protection Essentials/Analytic Rules/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
id: f6502545-ae3a-4232-a8b0-79d87e5c98d7
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'  
triggerThreshold: 0
entityMappings:
- fieldMappings:
  - columnName: TargetObject
    identifier: Key
  entityType: RegistryKey
- fieldMappings:
  - columnName: Computer
    identifier: FullName
  - columnName: HostName
    identifier: HostName
  - columnName: DnsDomain
    identifier: DnsDomain
  entityType: Host
version: 1.0.3
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),'')  
tactics:
- CredentialAccess
kind: Scheduled
queryFrequency: 1h
severity: Medium
queryPeriod: 1h
requiredDataConnectors:
- dataTypes:
  - SecurityEvent
  connectorId: SecurityEvents
- dataTypes:
  - SecurityEvent
  connectorId: WindowsSecurityEvents
status: Available
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Endpoint Threat Protection Essentials/Analytic Rules/WDigestDowngradeAttack.yaml
relevantTechniques:
- T1003

ARM