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Suspicious WerFault Child Process
editSuspicious WerFault Child Process
editA 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.
Rule type: eql
Rule indices:
- winlogbeat-*
- logs-endpoint.events.*
- logs-windows.*
- endgame-*
Severity: medium
Risk score: 47
Runs every: 5m
Searches indices from: now-9m (Date Math format, see also Additional look-back time)
Maximum alerts per execution: 100
References:
- https://www.hexacorn.com/blog/2019/09/19/silentprocessexit-quick-look-under-the-hood/
- https://www.hexacorn.com/blog/2019/09/20/werfault-command-line-switches-v0-1/
- https://github.com/sbousseaden/EVTX-ATTACK-SAMPLES/blob/master/Persistence/persistence_SilentProcessExit_ImageHijack_sysmon_13_1.evtx
- https://web.archive.org/web/20230530011556/https://web.archive.org/web/20230530011556/https://blog.menasec.net/2021/01/
Tags:
- Domain: Endpoint
- OS: Windows
- Use Case: Threat Detection
- Tactic: Defense Evasion
- Tactic: Persistence
- Tactic: Privilege Escalation
- Data Source: Elastic Endgame
- Data Source: Elastic Defend
Version: 110
Rule authors:
- Elastic
Rule license: Elastic License v2
Rule query
editprocess 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")
Framework: 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/
-
Tactic:
- Name: Persistence
- ID: TA0003
- Reference URL: https://attack.mitre.org/tactics/TA0003/
-
Technique:
- Name: Event Triggered Execution
- ID: T1546
- Reference URL: https://attack.mitre.org/techniques/T1546/
-
Sub-technique:
- Name: Image File Execution Options Injection
- ID: T1546.012
- Reference URL: https://attack.mitre.org/techniques/T1546/012/
-
Tactic:
- Name: Privilege Escalation
- ID: TA0004
- Reference URL: https://attack.mitre.org/tactics/TA0004/
-
Technique:
- Name: Event Triggered Execution
- ID: T1546
- Reference URL: https://attack.mitre.org/techniques/T1546/
-
Sub-technique:
- Name: Image File Execution Options Injection
- ID: T1546.012
- Reference URL: https://attack.mitre.org/techniques/T1546/012/