Wdigest CredGuard Registry Modification

Status: test
Severity: high
Log source: category registry_event, product windows
Author: Roberto Rodriguez (Cyb3rWard0g), OTR (Open Threat Research)
Source: github.com/SigmaHQ/sigma

Detects potential malicious modification of the property value of IsCredGuardEnabled from HKLM:\SYSTEM\CurrentControlSet\Control\SecurityProviders\WDigest to disable Cred Guard on a system. This is usually used with UseLogonCredential to manipulate the caching credentials.

MITRE ATT&CK coverage

Tactic	Techniques
Persistence	`T1112` Modify Registry
Defense Impairment	`T1112` Modify Registry

Telemetry coverage

Provider	Record / event type
Sysmon	Event ID 12: RegistryEvent (Object create and delete)
Sysmon	Event ID 13: RegistryEvent (Value Set)
Sysmon	Event ID 14: RegistryEvent (Key and Value Rename)

Rule body

title: Wdigest CredGuard Registry Modification
id: 1a2d6c47-75b0-45bd-b133-2c0be75349fd
status: test
description: |
  Detects potential malicious modification of the property value of IsCredGuardEnabled from
  HKLM:\SYSTEM\CurrentControlSet\Control\SecurityProviders\WDigest to disable Cred Guard on a system.
  This is usually used with UseLogonCredential to manipulate the caching credentials.
references:
    - https://teamhydra.blog/2020/08/25/bypassing-credential-guard/
author: Roberto Rodriguez (Cyb3rWard0g), OTR (Open Threat Research)
date: 2019-08-25
modified: 2021-11-27
tags:
    - attack.persistence
    - attack.defense-impairment
    - attack.t1112
logsource:
    category: registry_event
    product: windows
detection:
    selection:
        TargetObject|endswith: '\IsCredGuardEnabled'
    condition: selection
falsepositives:
    - Unknown
level: high

Stages and Predicates

Stage 0: `condition`

selection

Stage 1: `selection`

selection:
    TargetObject|endswith: '\IsCredGuardEnabled'

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`TargetObject`	ends_with	`\IsCredGuardEnabled`	`field:"TargetObject" kind:ends_with value:"\IsCredGuardEnabled"`