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Detection rules › Sigma

LSA PPL Protection Setting Modification via CommandLine

Status
test
Severity
medium
Log source
product windows, category process_creation
Author
Florian Roth (Nextron Systems), Swachchhanda Shrawan Poudel (Nextron Systems)
Source
github.com/SigmaHQ/sigma

Detects modification of LSA PPL protection settings via CommandLine. It may indicate an attempt to disable protection and enable credential dumping tools to access LSASS process memory.

MITRE ATT&CK coverage

TacticTechniques
Defense ImpairmentT1689 Downgrade Attack

Event coverage

ProviderEventTitle
SysmonEvent ID 1Process creation

Rule body yaml

title: LSA PPL Protection Setting Modification via CommandLine
id: 8c0eca51-0f88-4db2-9183-fdfb10c703f9
status: test
description: |
    Detects modification of LSA PPL protection settings via CommandLine.
    It may indicate an attempt to disable protection and enable credential dumping tools to access LSASS process memory.
references:
    - https://thedfirreport.com/2022/03/21/apt35-automates-initial-access-using-proxyshell/
    - https://github.com/shoober420/windows11-scripts/blob/38d83331738cd713ccb42f2c4557d17a27aefd98/Windows11Tweaks.bat#L1825
author: Florian Roth (Nextron Systems), Swachchhanda Shrawan Poudel (Nextron Systems)
date: 2022-03-22
modified: 2026-03-13
tags:
    - attack.defense-impairment
    - attack.t1689
logsource:
    category: process_creation
    product: windows
detection:
    selection_img:
        - Image|endswith:
              - '\reg.exe'
              - '\powershell.exe'
              - '\pwsh.exe'
        - OriginalFileName:
              - 'reg.exe'
              - 'powershell.exe'
              - 'pwsh.dll'
    selection_cli_action:
        CommandLine|contains|all:
            - 'ControlSet'
            - '\Control\Lsa'
        CommandLine|contains:
            - 'Set-ItemProperty'
            - 'New-ItemProperty'
            - ' add '
    selection_key:
        CommandLine|contains:
            - 'IsPplAutoEnabled'
            - 'RunAsPPL'
            - 'RunAsPPLBoot'
    condition: all of selection_*
falsepositives:
    - Unlikely
level: medium

Stages and Predicates

Stage 0: condition

all of selection_*

Stage 1: selection_img

selection_img:
    - Image|endswith:
          - '\reg.exe'
          - '\powershell.exe'
          - '\pwsh.exe'
    - OriginalFileName:
          - 'reg.exe'
          - 'powershell.exe'
          - 'pwsh.dll'

Stage 2: selection_cli_action

selection_cli_action:
    CommandLine|contains|all:
        - 'ControlSet'
        - '\Control\Lsa'
    CommandLine|contains:
        - 'Set-ItemProperty'
        - 'New-ItemProperty'
        - ' add '

Stage 3: selection_key

selection_key:
    CommandLine|contains:
        - 'IsPplAutoEnabled'
        - 'RunAsPPL'
        - 'RunAsPPLBoot'

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
  • add corpus 14 (sigma 12, splunk 1, chronicle 1)
  • ControlSet corpus 3 (sigma 3)
  • IsPplAutoEnabled
  • New-ItemProperty corpus 7 (sigma 7)
  • RunAsPPL
  • RunAsPPLBoot
  • Set-ItemProperty corpus 7 (sigma 7)
  • \Control\Lsa corpus 2 (sigma 2)
Imageends_with
  • \powershell.exe corpus 182 (sigma 182)
  • \pwsh.exe corpus 168 (sigma 168)
  • \reg.exe corpus 58 (sigma 58)
OriginalFileNameeq
  • powershell.exe corpus 120 (sigma 84, splunk 30, elastic 6)
  • pwsh.dll corpus 112 (sigma 79, splunk 30, elastic 3)
  • reg.exe corpus 42 (sigma 32, splunk 8, elastic 2)