Credential Dumping Attempt Via WerFault — Sigma Rule

Rule metadata and linked tags

Author: Florian Roth (Nextron Systems). Source status: test; severity: high. Source dates: 2012-06-27 / 2023-11-29.

{
  "category": "process_access",
  "product": "windows"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: e7a546502881b53beefa9ae3588e297646363dd2897b11254a801b9431133a05

Detection logic

Original source YAML. Source-tag agreement is not proof of complete semantic coverage. This rule has not been compiled for a SIEM backend or validated against live telemetry here.

title: Credential Dumping Attempt Via WerFault
id: e5b33f7d-eb93-48b6-9851-09e1e610b6d7
status: test
description: Detects process LSASS memory dump using Mimikatz, NanoDump, Invoke-Mimikatz, Procdump or Taskmgr based on the CallTrace pointing to ntdll.dll, dbghelp.dll or dbgcore.dll for win10, server2016 and up.
references:
    - https://github.com/helpsystems/nanodump/commit/578116faea3d278d53d70ea932e2bbfe42569507
author: Florian Roth (Nextron Systems)
date: 2012-06-27
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

Original YAML and metadata in JSON

False positives

• Actual failures in lsass.exe that trigger a crash dump (unlikely)
• Unknown cases in which WerFault accesses lsass.exe

Source references

• https://github.com/helpsystems/nanodump/commit/578116faea3d278d53d70ea932e2bbfe42569507