Elastic Security Detection Rules

Suspicious WerFault Child Process

Last updated 5 months ago on 2025-03-20
Created 5 years ago on 2020-08-24

About

A suspicious WerFault child process was detected, which may indicate an attempt to run via the SilentProcessExit registry key manipulation. Verify process details such as command line, network connections and file writes.
Tags
Domain: EndpointOS: WindowsUse Case: Threat DetectionTactic: Defense EvasionTactic: PersistenceTactic: Privilege EscalationData Source: Elastic EndgameData Source: Elastic DefendData Source: Microsoft Defender for EndpointData Source: SysmonData Source: SentinelOneLanguage: eql
Severity
medium
Risk Score
47
MITRE ATT&CK™

Defense Evasion (TA0005)(opens in a new tab or window)

↳ Masquerading (T1036)(opens in a new tab or window)

Persistence (TA0003)(opens in a new tab or window)

↳ Event Triggered Execution (T1546)(opens in a new tab or window)

Privilege Escalation (TA0004)(opens in a new tab or window)

↳ Event Triggered Execution (T1546)(opens in a new tab or window)

False Positive Examples
Custom Windows error reporting debugger or applications restarted by WerFault after a crash.
License
Elastic License v2(opens in a new tab or window)

Definition

Rule Type
Event Correlation Rule
Integration Pack
Prebuilt Security Detection Rules
Index Patterns
winlogbeat-*logs-endpoint.events.process-*logs-windows.sysmon_operational-*endgame-*logs-sentinel_one_cloud_funnel.*logs-m365_defender.event-*
Related Integrations

endpoint(opens in a new tab or window)

windows(opens in a new tab or window)

sentinel_one_cloud_funnel(opens in a new tab or window)

m365_defender(opens in a new tab or window)

Query
process where host.os.type == "windows" and event.type == "start" and

  process.parent.name : "WerFault.exe" and

  /* args -s and -t used to execute a process via SilentProcessExit mechanism */
  (process.parent.args : "-s" and process.parent.args : "-t" and process.parent.args : "-c") and

  not process.executable : ("?:\\Windows\\SysWOW64\\Initcrypt.exe", "?:\\Program Files (x86)\\Heimdal\\Heimdal.Guard.exe")

Install detection rules in Elastic Security

Detect Suspicious WerFault Child Process in the Elastic Security detection engine by installing this rule into your Elastic Stack.

To setup this rule, check out the installation guide for Prebuilt Security Detection Rules(opens in a new tab or window).