Potential Windows Error Manager Masquerading
editPotential Windows Error Manager Masquerading
editIdentifies 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.
Rule type: eql
Rule indices:
- winlogbeat-*
- logs-endpoint.events.*
Severity: medium
Risk score: 47
Runs every: 5 minutes
Searches indices from: now-9m (Date Math format, see also Additional look-back time)
Maximum alerts per execution: 100
References:
Tags:
- Elastic
- Host
- Windows
- Threat Detection
- Defense Evasion
Version: 2 (version history)
Added (Elastic Stack release): 7.10.0
Last modified (Elastic Stack release): 7.11.0
Rule authors: Elastic
Rule license: Elastic License
Potential false positives
editLegit Application Crash with rare Werfault commandline value
Rule query
editsequence by host.id, process.entity_id with maxspan = 5s [process
where event.type:"start" and process.name : ("wermgr.exe",
"WerFault.exe") and process.args_count == 1] [network where
process.name : ("wermgr.exe", "WerFault.exe") and network.protocol !=
"dns" and network.direction == "outgoing" and destination.ip
!="::1" and destination.ip !="127.0.0.1" ]
Threat mapping
editFramework: MITRE ATT&CKTM
-
Tactic:
- Name: Defense Evasion
- ID: TA0005
- Reference URL: https://attack.mitre.org/tactics/TA0005/
-
Technique:
- Name: Masquerading
- ID: T1036
- Reference URL: https://attack.mitre.org/techniques/T1036/
Rule version history
edit- Version 2 (7.11.0 release)
-
- Rule name changed from: Process Potentially Masquerading as WerFault
-
Updated query, changed from:
event.category:process and event.type:(start or process_started) and process.name:WerFault.exe and not process.args:((("-u" or "-pss") and "-p" and "-s") or ("/h" and "/shared") or ("-k" and "-lcq"))