Detection: Windows MSIX Package Interaction

Updated Date: 2025-08-05 ID: 1a06689d-814e-4db2-b2c7-5a174f8c2d6d Author: Michael Haag, Splunk Type: Hunting Product: Splunk Enterprise Security

Description

This hunting query detects user interactions with MSIX packages by monitoring EventCode 171 in the Microsoft-Windows-AppXPackaging/Operational logs. These events are generated when a user clicks on or attempts to interact with an MSIX package, even if the package is not fully installed. This information can be valuable for security teams to identify what MSIX packages users are attempting to open in their environment, which may help detect malicious MSIX packages before they're fully installed. Monitoring these interactions can provide early warning of potential MSIX package abuse, which has been leveraged by threat actors such as FIN7, Zloader (Storm-0569), and FakeBat (Storm-1113).

Search

1`wineventlog_appxpackaging` EventCode=171 
2| stats count min(_time) as firstTime max(_time) as lastTime values(packageFullName) as packageFullName values(user_id) as user_id by host EventCode 
3| `security_content_ctime(firstTime)` 
4| `security_content_ctime(lastTime)` 
5| `windows_msix_package_interaction_filter`

Data Source

Name	Platform	Sourcetype	Source
Windows Event Log AppXPackaging 171	Windows	`'XmlWinEventLog'`	`'XmlWinEventLog:Microsoft-Windows-AppxPackaging/Operational'`

Macros Used

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

windows_msix_package_interaction_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
T1204.002	Malicious File	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	False

This configuration file applies to all detections of type hunting.

Implementation

To implement this detection, you need to be collecting Windows Event logs from the Microsoft-Windows-AppXPackaging/Operational channel. In Splunk, this typically requires the Windows TA and configuration to collect from this specific channel. Ensure your Windows event collection is properly configured to capture EventCode 171 from the Microsoft-Windows-AppXPackaging/Operational log. This query is designed as a hunting query to help identify MSIX package interactions across your environment.

Known False Positives

This hunting query will detect legitimate MSIX package interactions from normal users. It is not designed to specifically identify malicious activity but rather to provide visibility into all MSIX package interactions. Security teams should review the results and look for unusual patterns, unexpected packages, or suspicious file paths.

Associated Analytic Story

MSIX Package Abuse

References

Detection Testing

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