Elastic Security Detection Rules

Potential Windows Error Manager Masquerading

Last updated 9 days ago on 2025-05-05
Created 5 years ago on 2020-08-24

About

Identifies suspicious instances of the Windows Error Reporting process (WerFault.exe or Wermgr.exe) with matching command-line and process executable values performing outgoing network connections. This may be indicative of a masquerading attempt to evade suspicious child process behavior detections.
Tags
Domain: EndpointOS: WindowsUse Case: Threat DetectionTactic: Defense EvasionData Source: Elastic DefendData Source: SysmonLanguage: 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)

False Positive Examples
Legit Application Crash with rare Werfault commandline value
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-endpoint.events.network-*logs-windows.sysmon_operational-*
Related Integrations

endpoint(opens in a new tab or window)

windows(opens in a new tab or window)

Query
sequence by host.id, process.entity_id with maxspan = 5s
  [process where host.os.type == "windows" and event.type:"start" and process.name : ("wermgr.exe", "WerFault.exe") and process.args_count == 1]
  [network where host.os.type == "windows" and process.name : ("wermgr.exe", "WerFault.exe") and network.protocol != "dns" and
    network.direction : ("outgoing", "egress") and destination.ip !="::1" and destination.ip !="127.0.0.1"
  ]

Install detection rules in Elastic Security

Detect Potential Windows Error Manager Masquerading 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).