Detection rules › Sigma

Windows Credential Guard Registry Tampering Via CommandLine

Severity
high
Author
Swachchhanda Shrawan Poudel (Nextron Systems)
Source
upstream

Detects attempts to add, modify, or delete Windows Credential Guard related registry keys or values via command line tools such as Reg.exe or PowerShell. Credential Guard uses virtualization-based security to isolate secrets so that only privileged system software can access them. Adversaries may disable Credential Guard to gain access to sensitive credentials stored in the system, such as NTLM hashes and Kerberos tickets, which can be used for lateral movement and privilege escalation. The rule matches suspicious command lines that target DeviceGuard or LSA registry paths and manipulate keys like EnableVirtualizationBasedSecurity, RequirePlatformSecurityFeatures, or LsaCfgFlags. Such activity may indicate an attempt to disable or tamper with Credential Guard, potentially exposing sensitive credentials for misuse.

MITRE ATT&CK coverage

TacticTechniques
Defense EvasionT1562.001 Impair Defenses: Disable or Modify Tools

Event coverage

ProviderEvent IDTitle
Sysmon1Process creation

Stages and Predicates

Stage 1: all of selection_img

or:
Image|endswith: '\powershell.exe'
Image|endswith: '\pwsh.exe'
Image|endswith: '\reg.exe'
OriginalFileName: PowerShell.EXE
OriginalFileName: pwsh.dll
OriginalFileName: reg.exe

Stage 2: all of selection_cli

or:
CommandLine|contains: 'New-ItemProperty '
CommandLine|contains: 'Remove-ItemProperty '
CommandLine|contains: 'Set-ItemProperty '
CommandLine|contains: 'add '
CommandLine|contains: 'del '
CommandLine|contains: 'delete '
CommandLine|contains: 'rp '
CommandLine|contains: 'si '

Stage 3: all of selection_key_base

or:
CommandLine|contains: 'Software\Policies\Microsoft\Windows\DeviceGuard'
CommandLine|contains: '\Control\DeviceGuard'
CommandLine|contains: '\Control\LSA'

Stage 4: all of selection_key_specific

or:
CommandLine|contains: 'EnableVirtualizationBasedSecurity'
CommandLine|contains: LsaCfgFlags
CommandLine|contains: RequirePlatformSecurityFeatures

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
CommandLinematch
  • EnableVirtualizationBasedSecurity corpus 2 (sigma 2)
  • LsaCfgFlags
  • New-ItemProperty corpus 3 (sigma 3)
  • Remove-ItemProperty
  • RequirePlatformSecurityFeatures
  • Set-ItemProperty corpus 3 (sigma 3)
  • Software\Policies\Microsoft\Windows\DeviceGuard
  • \Control\DeviceGuard
  • \Control\LSA
  • add corpus 9 (sigma 9)
  • del corpus 5 (sigma 5)
  • delete corpus 4 (sigma 4)
  • rp
  • si corpus 4 (sigma 4)
Imageends_with
  • \powershell.exe corpus 143 (sigma 143)
  • \pwsh.exe corpus 140 (sigma 140)
  • \reg.exe corpus 46 (sigma 46)
OriginalFileNameeq
  • PowerShell.EXE corpus 64 (sigma 60, splunk 4)
  • pwsh.dll corpus 72 (sigma 68, splunk 4)
  • reg.exe corpus 29 (sigma 29)