Windows Process Access Indicates Potential Shellcode Injection via LSASS

Alerts on high-privilege process access from wmiprvse.exe to lsass.exe consistent with potential shellcode injection behavior.

FreeReviewedSigma · Medium · v7
Product
windows
Category
process_access
Author
Bhabesh Raj (SigmaHQ), DRL 1.1
Published
2022-03-11
Updated
2026-09-15
title: Windows Process Access Indicates Potential Shellcode Injection via LSASS
id: f07d0001-9fd8-410d-9419-a5f0b9788428
status: test
description: This rule flags Windows process access events where the caller requests specific GrantedAccess values that are consistent with potential shellcode injection behavior, with a CallTrace containing 'UNKNOWN'. It excludes several known benign process relationships, including interactions involving Wbem Wmiprvse.exe to lsass.exe and certain Dell, Visual Studio, Avira, or service shell scenarios. Telemetry relies on process access auditing that includes GrantedAccess, SourceImage, TargetImage, and CallTrace.
references:
  - https://github.com/EmpireProject/PSInject
  - https://github.com/SigmaHQ/sigma/blob/master/rules-threat-hunting/windows/process_access/proc_access_win_susp_potential_shellcode_injection.yml
author: Bhabesh Raj, Huntrule Team
date: 2022-03-11
modified: 2026-09-15
tags:
  - attack.privilege-escalation
  - attack.stealth
  - attack.t1055
  - detection.threat-hunting
logsource:
  category: process_access
  product: windows
detection:
  selection:
    GrantedAccess:
      - "0x147a"
      - "0x1f3fff"
    CallTrace|contains: UNKNOWN
  filter_main_wmiprvse:
    SourceImage: C:\Windows\System32\Wbem\Wmiprvse.exe
    TargetImage: C:\Windows\system32\lsass.exe
  filter_optional_dell_folders:
    SourceImage|startswith:
      - C:\Program Files\Dell\
      - C:\Program Files (x86)\Dell\
    TargetImage|startswith:
      - C:\Program Files\Dell\
      - C:\Program Files (x86)\Dell\
  filter_optional_dell_specifc:
    SourceImage: C:\Program Files (x86)\Dell\UpdateService\ServiceShell.exe
    TargetImage: C:\Windows\Explorer.EXE
  filter_optional_visual_studio:
    SourceImage|startswith: C:\Program Files\Microsoft Visual Studio\
    TargetImage|startswith: C:\Program Files\Microsoft Visual Studio\
  filter_optional_avira:
    SourceImage|contains: \Avira
    TargetImage|contains: \Avira\
  condition: selection and not 1 of filter_main_* and not 1 of filter_optional_*
falsepositives:
  - Unknown
level: medium
license: DRL-1.1
related:
  - id: 250ae82f-736e-4844-a68b-0b5e8cc887da
    type: derived