GitHub Repo

Detection: Splunk RCE PDFgen Render

DEPRECATED DETECTION

This detection has been marked as deprecated by the Splunk Threat Research team. This means that it will no longer be maintained or supported. If you have any questions or concerns, please reach out to us at research@splunk.com.

Updated Date: 2026-06-24 ID: bc2b7437-0400-438b-9537-21ab5b7d2d53 Author: Rod Soto, Chase Franklin Type: TTP Product: Splunk Enterprise Security

Description

This is a hunting search designed to find and discover exploitation attempts against Splunk pdfgen render endpoint which results in remote

1index=_internal sourcetype=splunk_pdfgen _raw IN ("*base64*", "*lambda*", "*system*") 
2| stats count min(_time) as firstTime max(_time) as lastTime by index, sourcetype, host, _raw 
3| `security_content_ctime(firstTime)` 
4| `security_content_ctime(lastTime)` 
5| `splunk_rce_pdfgen_render_filter`

Data Source

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

Macros Used

Name Value
security_content_ctime convert timeformat="%Y-%m-%dT%H:%M:%S" ctime($field$)
splunk_rce_pdfgen_render_filter search *
splunk_rce_pdfgen_render_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
T1210 Exploitation of Remote Services Lateral Movement
Exploitation
DE.CM
CIS 10

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 0 * * * *
Earliest Time -70m@m
Latest Time -10m@m
Schedule Window auto
Creates Finding (Notable) Yes
Rule Title %name%
Rule Description %description%
Notable Event Fields user, dest
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 indexes.

Known False Positives

This search will hunt for exploitation attempts against Splunk PDFgen render function, and not all requests are necesarily malicious so there will be false positives.

Associated Analytic Story

Finding

Title Entity Field Entity Type Risk Score
Possible exploitation against $host$ host system 80

References

Detection Testing

Test Type Status Dataset Source Sourcetype
Validation Not Applicable N/A N/A N/A
Unit ✅ Passing Dataset /opt/splunk/var/log/splunk/pdfgen.log splunk_pdfgen
Integration ❌ Failing Dataset /opt/splunk/var/log/splunk/pdfgen.log splunk_pdfgen

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: 8