Windows process access indicating potential shellcode injection to lsass.exe
Alerts on high-privilege process access from wmiprvse.exe to lsass.exe consistent with potential shellcode injection behavior.
- Product
- windows
- Category
- process_access
- Author
- Bhabesh Raj (SigmaHQ), DRL 1.1
- Published
- 2022-03-11
- Updated
- 2026-07-31
ATT&CK techniques
Priv Esc → Defense EvasionRecon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact
What it detects
This rule flags Windows process access events with specific GrantedAccess values and an associated call trace containing the string "UNKNOWN". The match is constrained to suspicious source/target process pairs involving Wmiprvse.exe accessing lsass.exe, while excluding several known benign Dell and Visual Studio program-to-program patterns. It matters because abnormal access to sensitive processes like lsass.exe can be used to support covert code execution, and the detection relies on process access telemetry that records GrantedAccess, SourceImage, TargetImage, and call trace context.
Reporting behind it
Changelog
v5- v5Candidate ingested via manual entry.2026-07-31
- v4Candidate ingested via manual entry.2026-07-31
- v3Candidate ingested via manual entry.2026-07-31
- v2Candidate ingested via manual entry.2026-07-31
- v1No changelog recorded for this version.2026-07-30
Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.
title: Windows process access indicating potential shellcode injection to lsass.exe
id: f07d0001-9fd8-410d-9419-a5f0b9788428
status: test
description: This rule flags Windows process access events with specific GrantedAccess values and an associated call trace containing the string "UNKNOWN". The match is constrained to suspicious source/target process pairs involving Wmiprvse.exe accessing lsass.exe, while excluding several known benign Dell and Visual Studio program-to-program patterns. It matters because abnormal access to sensitive processes like lsass.exe can be used to support covert code execution, and the detection relies on process access telemetry that records GrantedAccess, SourceImage, TargetImage, and call trace context.
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: 2024-07-02
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\
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