Detection: Windows Application Whitelisting Bypass Attempt via Rundll32

Updated Date: 2025-10-06 ID: 1ef5dab0-e1f1-495d-a272-d134583c10b1 Author: Michael Haag, Splunk Type: TTP Product: Splunk Enterprise Security

Description

The following analytic detects the execution of rundll32.exe calling one of the following DLLs:

Advpack.dll
Ieadvpack.dll
Syssetup.dll
Setupapi.dll

with one of the following functions: "LaunchINFSection", "InstallHinfSection", "SetupInfObjectInstallAction". This method is identified through Endpoint Detection and Response (EDR) telemetry, focusing on command-line executions and process details. This activity is significant as it indicates a potential application control or whitelisting bypass, allowing script code execution from a file. If confirmed malicious, an attacker could execute arbitrary code, potentially leading to privilege escalation, persistence, or further network compromise. Investigate the script content, network connections, and any spawned child processes for further context.

Search

 1
 2| tstats `security_content_summariesonly` 
 3  count min(_time) as firstTime 
 4  max(_time) as lastTime 
 5from datamodel=Endpoint.Processes where 
 6`process_rundll32` 
 7Processes.process IN ("*syssetup*", "*advpack*", "*setupapi*")
 8Processes.process IN ("*LaunchINFSection*", "*InstallHinfSection*", "*SetupInfObjectInstallAction*")
 9by Processes.action Processes.dest Processes.original_file_name Processes.parent_process
10   Processes.parent_process_exec Processes.parent_process_guid Processes.parent_process_id
11   Processes.parent_process_name Processes.parent_process_path Processes.process Processes.process_exec
12   Processes.process_guid Processes.process_hash Processes.process_id Processes.process_integrity_level
13   Processes.process_name Processes.process_path Processes.user Processes.user_id Processes.vendor_product
14
15| `drop_dm_object_name(Processes)` 
16
17| `security_content_ctime(firstTime)` 
18
19| `security_content_ctime(lastTime)`
20
21| `windows_application_whitelisting_bypass_attempt_via_rundll32_filter`

Data Source

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

Macros Used

Name	Value
process_rundll32	`(Processes.process_name=rundll32.exe OR Processes.original_file_name=RUNDLL32.EXE)`
windows_application_whitelisting_bypass_attempt_via_rundll32_filter	`search *`

windows_application_whitelisting_bypass_attempt_via_rundll32_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
T1218.011	Rundll32	Defense Evasion

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 Notable	Yes
Rule Title	`%name%`
Rule Description	`%description%`
Notable Event Fields	user, dest
Creates Risk Event	True

This configuration file applies to all detections of type TTP. These detections will use Risk Based Alerting and generate Notable Events.

Implementation

The detection is based on data that originates from Endpoint Detection and Response (EDR) agents. These agents are designed to provide security-related telemetry from the endpoints where the agent is installed. To implement this search, you must ingest logs that contain the process GUID, process name, and parent process. Additionally, you must ingest complete command-line executions. These logs must be processed using the appropriate Splunk Technology Add-ons that are specific to the EDR product. The logs must also be mapped to the Processes node of the Endpoint data model. Use the Splunk Common Information Model (CIM) to normalize the field names and speed up the data modeling process.

Known False Positives

Although unlikely, some legitimate applications may leverage one of the following DLLs syssetup.dll, dvpack.dll, ieadvpack.dll and can trigger a false positive. Apply additional filters as needed.

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message:

An instance of $parent_process_name$ spawning $process_name$ loading syssetup.dll by calling the LaunchINFSection function on the command line was identified on endpoint $dest$ by user $user$.

Risk Object	Risk Object Type	Risk Score	Threat Objects
dest	system	80	parent_process_name, process_name
user	user	80	parent_process_name, process_name

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