Detection: Windows App Layer Protocol Wermgr Connect To NamedPipe

Updated Date: 2024-09-30 ID: 2f3a4092-548b-421c-9caa-84918e1787ef Author: Teoderick Contreras, Splunk Type: Anomaly Product: Splunk Enterprise Security

Description

The following analytic detects the wermgr.exe process creating or connecting to a named pipe. It leverages Sysmon EventCodes 17 and 18 to identify these actions. This activity is significant because wermgr.exe, a legitimate Windows OS Problem Reporting application, is often abused by malware such as Trickbot and Qakbot to execute malicious code. If confirmed malicious, this behavior could indicate that an attacker has injected code into wermgr.exe, potentially allowing them to communicate covertly, escalate privileges, or persist within the environment.

1`sysmon` EventCode IN (17, 18) Image= "*\\wermgr.exe" EventType IN ( "CreatePipe", "ConnectPipe") 
2| stats  min(_time) as firstTime max(_time) as lastTime count by Image EventType ProcessGuid ProcessId PipeName SecurityID EventCode dest UserID 
3| `security_content_ctime(firstTime)` 
4| `security_content_ctime(lastTime)` 
5| `windows_app_layer_protocol_wermgr_connect_to_namedpipe_filter`

Data Source

Name Platform Sourcetype Source
Sysmon EventID 17 Windows icon Windows 'xmlwineventlog' 'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational'
Sysmon EventID 18 Windows icon Windows 'xmlwineventlog' 'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational'

Macros Used

Name Value
security_content_ctime convert timeformat="%Y-%m-%dT%H:%M:%S" ctime($field$)
windows_app_layer_protocol_wermgr_connect_to_namedpipe_filter search *
windows_app_layer_protocol_wermgr_connect_to_namedpipe_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
T1071 Application Layer Protocol Command And Control
KillChainPhase.COMMAND_AND_CONTROL
NistCategory.DE_AE
Cis18Value.CIS_10
INC Ransom
Magic Hound
Rocke
TeamTNT

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 Risk Event True
This configuration file applies to all detections of type anomaly. These detections will use Risk Based Alerting.

Implementation

To successfully implement this search, you need to be ingesting logs with the process name, pipename, processguid and named pipe event type from your endpoints. If you are using Sysmon, you must have at least version 6.0.4 of the Sysmon TA.

Known False Positives

unknown

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message Risk Score Impact Confidence
wermgr.exe process is creating or connecting to a named pipe $PipeName$ in $dest$ 49 70 70
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

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: 3