GitHub Repo

Detection: Splunk unnecessary file extensions allowed by lookup table uploads

REMOVED DETECTION

This detection has been removed from the Splunk Threat Research content library and is no longer maintained or supported.

Reason: Detection is deprecated as the associated CVEs have been patched in the latest Splunk release.

Removed in version: 5.6.0

If you have any questions or concerns, please reach out to us at research@splunk.com.

Updated Date: 2026-05-14 ID: b7d1293f-e78f-415e-b5f6-443df3480082 Author: Rod Soto, Splunk Type: TTP Product: Splunk Enterprise Security

Description

The following analytic identifies user activity related to uploading lookup tables with unnecessary filename extensions in Splunk Enterprise versions below 8.1.13, 8.2.10, and 9.0.4. It detects this activity by monitoring HTTP methods (POST, DELETE) and specific URI paths in the internal splunkd_access logs. This behavior is significant because it can indicate attempts to upload potentially malicious files disguised as lookup tables. If confirmed malicious, this activity could allow an attacker to execute unauthorized code or manipulate data within the Splunk environment, leading to potential data breaches or system compromise.

1`splunkda` method IN ("POST", "DELETE") uri_path=/servicesNS/*/ui/views/* 
2| eval activity = case( method=="POST" AND like( uri_path , "%/acl" ) , "Permissions Update", method=="POST" AND NOT like( uri_path , "%/acl" ) , "Edited" , method=="DELETE" , "Deleted" ) 
3| rex field=uri_path "(?<user_and_app>.*?)\/ui\/views/(?<dashboard_encoded>.*)" 
4| eval dashboard = urldecode( dashboard_encoded ) 
5| table _time, uri_path, user, dashboard, activity, uri_path 
6| `splunk_unnecessary_file_extensions_allowed_by_lookup_table_uploads_filter`

Data Source

Name Platform Sourcetype Source
Splunk Splunk icon Splunk 'splunkd_ui_access' 'splunkd_ui_access.log'

Macros Used

Name Value
splunkda index=_internal sourcetype=splunkd_access
splunk_unnecessary_file_extensions_allowed_by_lookup_table_uploads_filter ``
splunk_unnecessary_file_extensions_allowed_by_lookup_table_uploads_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
T1189 Drive-by Compromise Initial Access

CVE

Default Configuration

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

Setting Value
Disabled true
Cron Schedule N/A
Earliest Time N/A
Latest Time N/A
Schedule Window N/A
Creates Finding (Notable) No
Creates Intermediate Finding (Risk Event) No
TTP detections generate a Finding (Notable) and may generate Intermediate Findings (Risk Events) for associated entities.

Implementation

Requires access to internal splunkd_access.

Known False Positives

This is a hunting search, the search provides information on upload, edit, and delete activity on Lookup Tables. Manual investigation is necessary after executing search. This search will produce false positives as payload cannot be directly discerned.

Associated Analytic Story

References

Detection Testing

Test Type Status Dataset Source Sourcetype
Validation Not Applicable N/A N/A N/A
Unit Not Applicable N/A N/A N/A
Integration Not Applicable N/A N/A N/A

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: 6