Detection: Windows Cloud Files Filter Loaded by Uncommon Process

Updated Date: 2026-05-18 ID: 77b85062-274e-43a5-9dab-c25862b85291 Author: Raven Tait, Splunk Type: Anomaly Product: Splunk Enterprise Security

Description

The following analytic detects cldapi.dll being loaded by a process not associated with legitimate cloud sync activity. The Windows Cloud Files API (cldapi.dll) is abused by several local privilege escalation exploits.

Search

 1`sysmon`
 2EventID=7
 3ImageLoaded="*\\cldapi.dll"
 4NOT Image IN (
 5  "*\\box.exe",
 6  "*\\dropbox.exe",
 7  "*\\googledrivefs.exe",
 8  "*\\icloud.exe",
 9  "*\\onedrive*.exe",
10  "*\\Windows\\explorer.exe"
11  "*\\Windows\\System32\\*",
12  "*\\Windows\\Syswow64\\*",
13  "*\\Windows\\WinSxS\\*"
14)
15
16| stats count min(_time) as firstTime
17                max(_time) as lastTime
18    by Computer ImageLoaded EventID dest loaded_file loaded_file_path process_exec
19       process_guid process_hash process_id process_name process_path
20       service_dll_signature_exists service_dll_signature_verified signature_id user_id
21       vendor_product
22
23| `security_content_ctime(firstTime)`
24
25| `security_content_ctime(lastTime)`
26
27| `windows_cloud_files_filter_loaded_by_uncommon_process_filter`

Data Source

Name	Platform	Sourcetype	Source
Sysmon EventID 7	Windows	`'XmlWinEventLog'`	`'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational'`

Macros Used

Name	Value
sysmon	`(source=WinEventLog:Microsoft-Windows-Sysmon/Operational OR source=XmlWinEventLog:Microsoft-Windows-Sysmon/Operational OR source=Syslog:Linux-Sysmon/Operational)`
windows_cloud_files_filter_loaded_by_uncommon_process_filter	`search *`

windows_cloud_files_filter_loaded_by_uncommon_process_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
T1543.003	Windows Service	Persistence

Exploitation

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 Finding (Notable)	No
Creates Intermediate Finding (Risk Event)	Yes

Anomaly detections generate Intermediate Findings (Risk Events). They do not generate a Finding (Notable) directly.

Implementation

To successfully implement this search, you need to be ingesting logs with the driver loaded and Signature from your endpoints. If you are using Sysmon, you must have at least version 6.0.4 of the Sysmon TA.

Known False Positives

False positives may include other third-party cloud-based file storage software. Filter as necessary for your environment.

Associated Analytic Story

Intermediate Findings

Message	Entity Field	Entity Type	Risk Score
Cloud Files Filter ($ImageLoaded$) loaded by suspicious process $Image$ on $dest$	dest	system	20

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