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

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

ARM