WerFault lsass.exe access indicating credential dumping attempts on Windows

Alert on WerFault.exe gaining broad access to lsass.exe, consistent with credential dumping attempts.

FreeReviewedSigma · High · v4

Product: windows
Category: process_access
Author: Florian Roth (Nextron Systems) (SigmaHQ), DRL 1.1
Published: 2022-06-27
Updated: 2026-09-24

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 flags process access where WerFault.exe accesses lsass.exe with broad granted permissions, matching behavior commonly seen during attempts to obtain credential material from LSASS. Attackers can use crash-dump style workflows to capture LSASS memory and then extract credentials. It relies on Windows process access telemetry with SourceImage/TargetImage path endings and the GrantedAccess value.

Reporting behind it

Related detections9 linkedT1003.001 — drag to rearrange

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Suspicious LSASS Memory Dump via Task Manager After Ivanti Exploitation

Suspicious ProcDump LSASS Memory Dump via process_creation

Malicious Mimikatz Credential Dump Log File Creation (via file_event)

Malicious WDigest UseLogonCredential Enabled for Cleartext Credential Theft (via registry_set)

WerFault lsass.exe access indicating credential dumping attempts on Windows

Pivot detection · T1003.001 · 9 related

Changelog

v4
Candidate ingested via manual entry.2026-09-24
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-werfault-triggered-lsass-access-for-credential-dumping-e5b33f7d

title: WerFault lsass.exe access indicating credential dumping attempts on Windows
id: af2a2616-846c-40d5-80d1-d06b33e46ddb
status: test
description: This rule flags process access where WerFault.exe accesses lsass.exe with broad granted permissions, matching behavior commonly seen during attempts to obtain credential material from LSASS. Attackers can use crash-dump style workflows to capture LSASS memory and then extract credentials. It relies on Windows process access telemetry with SourceImage/TargetImage path endings and the GrantedAccess value.
references:
  - https://github.com/helpsystems/nanodump/commit/578116faea3d278d53d70ea932e2bbfe42569507
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_access/proc_access_win_lsass_werfault.yml
author: Florian Roth (Nextron Systems), Huntrule Team
date: 2022-06-27
modified: 2023-11-29
tags:
  - attack.credential-access
  - attack.t1003.001
  - attack.s0002
logsource:
  category: process_access
  product: windows
detection:
  selection:
    SourceImage|endswith: \WerFault.exe
    TargetImage|endswith: \lsass.exe
    GrantedAccess: "0x1FFFFF"
  condition: selection
falsepositives:
  - Actual failures in lsass.exe that trigger a crash dump (unlikely)
  - Unknown cases in which WerFault accesses lsass.exe
level: high
license: DRL-1.1
related:
  - id: e5b33f7d-eb93-48b6-9851-09e1e610b6d7
    type: derived

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