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Description

The following analytic identifies attempts to exploit a deserialization vulnerability in Splunk Enterprise for Windows versions below 9.0.8 and 9.1.3. It detects irregular path file executions by analyzing splunk_python logs and extracting file paths and names. This activity is significant because it indicates potential exploitation of a known vulnerability, which could lead to arbitrary code execution. If confirmed malicious, an attacker could gain unauthorized access, execute arbitrary code, and potentially compromise the entire Splunk environment, leading to data breaches and further system exploitation.

  • Type: TTP

  • Product: Splunk Enterprise

  • Last Updated: 2024-07-01
  • Author: Rod Soto, Eric McGinnis, Chase Franklin
  • ID: 947d4d2e-1b64-41fc-b32a-736ddb88ce97

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1190 Exploit Public-Facing Application Initial Access
Kill Chain Phase
  • Delivery
NIST
  • DE.CM
CIS20
  • CIS 10
CVE 


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`splunk_python` request_path="/*/app/search/C:\\Program" *strings* 
| rex "request_path=(?<file_path>[^\"]+)" 
| rex field=file_path "[^\"]+/(?<file_name>[^\"\'\s/\\\\]+)" 
| stats min(_time) as firstTime max(_time) as lastTime values(file_path) as file_path values(file_name) as file_name by index, sourcetype, host 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `splunk_enterprise_windows_deserialization_file_partition_filter`

Macros

The SPL above uses the following Macros:

:information_source: splunk_enterprise_windows_deserialization_file_partition_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Required fields

List of fields required to use this analytic.

  • request_path
  • field
  • file_name
  • host

How To Implement

Requires access to internal indexes. This detection search will display irregular path file execution, which will display exploit attempts. Only applies to Microsoft Windows Splunk versions.

Known False Positives

Irregular path with files that may be purposely called for benign reasons may produce false positives.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
90.0 100 90 Possible Windows Deserialization exploitation via irregular path file against $host$

:information_source: The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

Reference

Test Dataset

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 | version: 3