Windows WSASS Process Execution via WerFaultSecure.EXE

Alerts on Windows process creation showing wsass.exe running with WerFaultSecure.exe and a PID-like argument.

FreeReviewedSigma · High · v2

Product: windows
Category: process_creation
Author: Swachchhanda Shrawan Poudel (Nextron Systems) (SigmaHQ), DRL 1.1
Published: 2025-11-23
Updated: 2026-07-31

ATT&CK techniques

Cred Access

Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
- T1003.001LSASS Memory
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule identifies execution of wsass.exe on Windows when its command line uses WerFaultSecure.exe, along with a PID argument. Attackers use this technique to facilitate LSASS memory dumping by leveraging Windows Error Reporting components to interact with protected processes. The detection relies on Windows process creation telemetry, including the executed image filename, an imphash match, and a command-line pattern that ties wsass.exe to werfaultsecure.exe and a numeric PID.

Reporting behind it

Related detections9 linkedT1003.001 — drag to rearrange

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Windows WSASS Process Execution via WerFaultSecure.EXE

Pivot detection · T1003.001 · 9 related

Changelog

v2
Candidate ingested via manual entry.2026-07-31
v1
No 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.

windows-detect-execution-of-wsass-exe-leveraging-werfaultsecure-exe-via-wer-589ac73f

title: Windows WSASS Process Execution via WerFaultSecure.EXE
id: 06a32785-20a9-4a9b-a562-7dda97480f85
status: experimental
description: This rule identifies execution of wsass.exe on Windows when its command line uses WerFaultSecure.exe, along with a PID argument. Attackers use this technique to facilitate LSASS memory dumping by leveraging Windows Error Reporting components to interact with protected processes. The detection relies on Windows process creation telemetry, including the executed image filename, an imphash match, and a command-line pattern that ties wsass.exe to werfaultsecure.exe and a numeric PID.
references:
  - https://github.com/TwoSevenOneT/WSASS
  - https://www.zerosalarium.com/2025/09/Dumping-LSASS-With-WER-On-Modern-Windows-11.html
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_creation/proc_creation_win_hktl_wsass.yml
author: Swachchhanda Shrawan Poudel (Nextron Systems), Huntrule Team
date: 2025-11-23
modified: 2026-01-09
tags:
  - attack.credential-access
  - attack.t1003.001
logsource:
  category: process_creation
  product: windows
detection:
  selection_img:
    Image|endswith: \wsass.exe
  selection_hash:
    Hashes|contains: IMPHASH=32F5095C9BBDCACF28FD4060EB4DFC42
  selection_cli:
    CommandLine|re: (?i)\.exe[\"\']?\s+[^\"]{0,64}werfaultsecure\.exe[\"\']?\s+\d{2,10}
  condition: 1 of selection_*
falsepositives:
  - Unlikely
level: high
regression_tests_path: regression_data/rules/windows/process_creation/proc_creation_win_hktl_wsass/info.yml
license: DRL-1.1
related:
  - id: 589ac73f-8e12-409c-964e-31a2f5775ae2
    type: derived

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