Detection: Windows Wermgr Spawning System Integrity Process

Updated Date: 2026-08-18 ID: d39634c8-7ce7-4503-a5da-73ca3c758fb9 Author: Onur Mustafa Erdogan, Splunk Type: TTP Product: Splunk Enterprise Security

Description

The following analytic detects WerMgr.exe (Windows Error Reporting) spawning a child process running at SYSTEM integrity level. WerMgr.exe normally runs at the integrity level of the reporting user or as a background SYSTEM-owned service that does not launch interactive children. In the ShieldBreak exploit, WerMgr.exe is manually triggered via the QueueReporting scheduled task and loads an attacker-planted phantom DLL (phoneinfo.dll), which then spawns an elevated shell. If confirmed malicious, this activity indicates successful local privilege escalation to SYSTEM.

Search

 1
 2| tstats `security_content_summariesonly`
 3  count min(_time) as firstTime
 4        max(_time) as lastTime
 5
 6from datamodel=Endpoint.Processes where
 7
 8Processes.parent_process_name="WerMgr.exe"
 9(
10    Processes.process_integrity_level="System"
11    OR
12    Processes.user IN ("*$", "System")
13)
14
15by Processes.action Processes.dest Processes.parent_process_name Processes.parent_process_path
16   Processes.parent_process Processes.parent_process_id Processes.process_name
17   Processes.process_path Processes.process Processes.process_id Processes.process_hash
18   Processes.process_integrity_level Processes.user Processes.vendor_product
19
20
21| `drop_dm_object_name(Processes)`
22
23| `security_content_ctime(firstTime)`
24
25| `security_content_ctime(lastTime)`
26
27| `windows_wermgr_spawning_system_integrity_process_filter`

Data Source

Name	Platform	Sourcetype	Source
Sysmon EventID 1	Windows	`'XmlWinEventLog'`	`'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational'`
CrowdStrike ProcessRollup2	Other	`'crowdstrike:events:sensor'`	`'crowdstrike'`
Windows Event Log Security 4688	Windows	`'XmlWinEventLog'`	`'XmlWinEventLog:Security'`

Macros Used

Name	Value
security_content_ctime	`convert timeformat="%Y-%m-%dT%H:%M:%S" ctime($field$)`
windows_wermgr_spawning_system_integrity_process_filter	`search *`

windows_wermgr_spawning_system_integrity_process_filter is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Annotations

- MITRE ATT&CK

+ Kill Chain Phases

+ NIST

+ CIS

- Threat Actors

ID	Technique	Tactic
T1068	Exploitation for Privilege Escalation	Privilege Escalation
T1134.001	Token Impersonation/Theft	Privilege Escalation

Exploitation

DE.CM

CIS 10

Default Configuration

This detection is configured by default in Splunk Enterprise Security to run with the following settings:

Setting	Value
Disabled	true
Cron Schedule	`0 * * * *`
Earliest Time	`-70m@m`
Latest Time	`-10m@m`
Schedule Window	`auto`
Creates Finding (Notable)	Yes
Rule Title	`%name%`
Rule Description	`%description%`
Notable Event Fields	user, dest
Creates Intermediate Finding (Risk Event)	No

TTP detections generate a Finding (Notable) and may generate Intermediate Findings (Risk Events) for associated entities.

Implementation

This detection is based on Process creation events. Make sure you are ingesting logs that contain parent process details and fields that indicate privilege level, such as user name or integrity level. If you are using Sysmon, make sure to enable logging of child processes of WerMgr.exe.

Known False Positives

No false positives have been identified at this time. WerMgr.exe spawning a SYSTEM-integrity child process is not expected under normal Windows Error Reporting operation.

Associated Analytic Story

Finding

Title	Entity Field	Entity Type	Risk Score
The [$parent_process_name$] process spawned [$process_name$] running at SYSTEM integrity level on $dest$	dest	system	50

Threat Objects

Field	Type
process_name	process_name
process	process

References

Detection Testing

Test Type	Status	Dataset	Source	Sourcetype
Validation	✅ Passing	N/A	N/A	N/A
Unit	✅ Passing	Dataset	`XmlWinEventLog:Microsoft-Windows-Sysmon/Operational`	`XmlWinEventLog`
Integration	✅ Passing	Dataset	`XmlWinEventLog:Microsoft-Windows-Sysmon/Operational`	`XmlWinEventLog`

Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

Source: GitHub |

Version: 1