Detection: Windows WMI Impersonate Token

Updated Date: 2024-11-13 ID: cf192860-2d94-40db-9a51-c04a2e8a8f8b Author: Teoderick Contreras, Splunk Type: Anomaly Product: Splunk Enterprise Security

Description

The following analytic detects potential WMI token impersonation activities in a process or command. It leverages Sysmon EventCode 10 to identify instances where wmiprvse.exe has a duplicate handle or full granted access in a target process. This behavior is significant as it is commonly used by malware like Qakbot for privilege escalation or defense evasion. If confirmed malicious, this activity could allow an attacker to gain elevated privileges, evade defenses, and maintain persistence within the environment.

Search

1`sysmon` EventCode=10 SourceImage = "*\\wmiprvse.exe"  GrantedAccess IN ("0x1478", "0x1fffff") 
2| stats count min(_time) as firstTime max(_time) as lastTime by SourceImage TargetImage SourceProcessGUID TargetProcessGUID SourceProcessId TargetProcessId GrantedAccess CallTrace dest 
3| `security_content_ctime(firstTime)` 
4| `security_content_ctime(lastTime)` 
5| `windows_wmi_impersonate_token_filter`

Data Source

Name	Platform	Sourcetype	Source
Sysmon EventID 10	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_wmi_impersonate_token_filter	`search *`

windows_wmi_impersonate_token_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
T1047	Windows Management Instrumentation	Execution

Installation

DE.AE

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 Risk Event	True

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

Implementation

This search requires Sysmon Logs and a Sysmon configuration, which includes EventCode 10. This search uses an input macro named sysmon. We strongly recommend that you specify your environment-specific configurations (index, source, sourcetype, etc.) for Windows Sysmon logs. Replace the macro definition with configurations for your Splunk environment. The search also uses a post-filter macro designed to filter out known false positives.

Known False Positives

administrator may execute impersonate wmi object script for auditing. Filter is needed.

Associated Analytic Story

Qakbot

Risk Based Analytics (RBA)

Risk Message:

wmiprvse.exe process having a duplicate or full Granted Access $GrantedAccess$ to $TargetImage$ process on $dest$

Risk Object	Risk Object Type	Risk Score	Threat Objects
dest	system	25	No Threat Objects

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: 4