GitHub Repo

Detection: Splunk Process Injection Forwarder Bundle Downloads

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This detection has been removed from the Splunk Threat Research content library and is no longer maintained or supported.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: 8ea57d78-1aac-45d2-a913-0cd603fb6e9e Author: Lou Stella, Splunk Type: Hunting Product: Splunk Enterprise Security

Description

The following analytic identifies unauthorized forwarder bundle downloads from Splunk Deployment Servers. It leverages native Splunk logs, specifically the splunkd component "PackageDownloadRestHandler," to detect instances where an unauthenticated client may have downloaded forwarder bundles. This activity is significant because it could indicate a potential security breach, allowing unauthorized access to sensitive configurations and applications. If confirmed malicious, an attacker could gain insights into the deployment server's environment, potentially leading to further exploitation or lateral movement within the network.

1`splunkd` component="PackageDownloadRestHandler" 
2| stats values(app) values(serverclass) by peer, host 
3| `splunk_process_injection_forwarder_bundle_downloads_filter`

Data Source

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

Macros Used

Name Value
splunkd index=_internal sourcetype=splunkd
splunk_process_injection_forwarder_bundle_downloads_filter ``
splunk_process_injection_forwarder_bundle_downloads_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
T1055 Process Injection Privilege Escalation

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
Hunting detections do not generate a Finding (Notable) or Intermediate Findings (Risk Events).

Implementation

This hunting search uses native logs produced when a deployment server is within your environment. Splunk SOAR customers can find a SOAR workbook that walks an analyst through the process of running these hunting searches in the references list of this detection. In order to use this workbook, a user will need to run a curl command to post the file to their SOAR instance such as "curl -u username:password https://soar.instance.name/rest/rest/workbook_template -d @splunk_psa_0622.json". A user should then create an empty container or case, attach the workbook, and begin working through the tasks.

Known False Positives

None at this time.

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

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