Detection: Windows Privilege Escalation Attempt Via MSI Rollback

Description

Detects an attacker abusing the Windows Installer rollback mechanism to escalate privileges from a standard user to SYSTEM without triggering a UAC prompt, using a technique known as FolderContentsDeleteToFolderDelete. Windows Installer (msiexec.exe) creates rollback scripts during software installation to undo changes if an installation fails. These rollback scripts are generated and executed by the Windows Installer service, which runs as SYSTEM. The FolderContentsDeleteToFolderDelete technique abuses this trusted mechanism by crafting a malicious rollback script that instructs the SYSTEM-level Installer service to delete attacker-chosen files or directories — effectively giving a low-privileged attacker the ability to make SYSTEM-level filesystem modifications without any privilege prompt.

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.process="*/target \"C:\\Config.msi\" *"
 9Processes.process="*/initial*"
10
11by Processes.process Processes.vendor_product Processes.user_id Processes.process_hash
12   Processes.parent_process_name Processes.parent_process_exec Processes.action
13   Processes.dest Processes.process_current_directory Processes.process_path
14   Processes.process_integrity_level Processes.original_file_name Processes.parent_process
15   Processes.parent_process_path Processes.parent_process_guid Processes.parent_process_id
16   Processes.process_guid Processes.process_id Processes.user Processes.process_name
17
18
19| `drop_dm_object_name(Processes)`
20
21| `security_content_ctime(firstTime)`
22
23| `security_content_ctime(lastTime)`
24
25| `windows_privilege_escalation_attempt_via_msi_rollback_filter`

Data Source

Name	Platform	Sourcetype	Source
CrowdStrike ProcessRollup2	Other	'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

Annotations

Default Configuration

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

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

Some legitimate system cleanup or maintenance scripts may use similar FolderContentsDeleteToFolderDelete commands. Review and whitelist approved tools to reduce false alerts.

Associated Analytic Story

• Windows Privilege Escalation

Risk Based Analytics (RBA)

Risk Message:

Potential MSI Rollback Privilege Escalation activity observed on $dest$ via $process$.

References

• https://github.com/mbog14/CVE-2024-44193

Detection Testing

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