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Description

This analytic identifies potentially malicious 'netsh' processes that manipulate firewall configurations. This behavior has been observed in the NJRAT malware, which deletes its added firewall rules as part of its cleanup process. Leveraging this anomaly detection can be a valuable approach for detecting malware, such as NJRAT, that makes alterations to firewall configurations as a component of its malicious activities.

  • Type: Anomaly
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel: Endpoint
  • Last Updated: 2023-09-08
  • Author: Teoderick Contreras, Splunk
  • ID: b188d11a-eba7-419d-b8b6-cc265b4f2c4f

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1562 Impair Defenses Defense Evasion
T1562.004 Disable or Modify System Firewall Defense Evasion
Kill Chain Phase
  • Exploitation
NIST
  • DE.AE
CIS20
  • CIS 10
CVE 


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| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where `process_netsh` Processes.process = "* firewall *" Processes.process = "* delete *" by Processes.parent_process Processes.parent_process_name Processes.process_name Processes.process_id Processes.process_guid Processes.process Processes.user Processes.dest 
| `drop_dm_object_name("Processes")` 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `windows_delete_or_modify_system_firewall_filter`

Macros

The SPL above uses the following Macros:

:information_source: windows_delete_or_modify_system_firewall_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.

  • _time
  • Processes.dest
  • Processes.user
  • Processes.parent_process_name
  • Processes.parent_process
  • Processes.process_name
  • Processes.process
  • Processes.process_id
  • Processes.parent_process_id

How To Implement

The detection is based on data that originates from Endpoint Detection and Response (EDR) agents. These agents are designed to provide security-related telemetry from the endpoints where the agent is installed. To implement this search, you must ingest logs that contain the process GUID, process name, and parent process. Additionally, you must ingest complete command-line executions. These logs must be processed using the appropriate Splunk Technology Add-ons that are specific to the EDR product. The logs must also be mapped to the Processes node of the Endpoint data model. Use the Splunk Common Information Model (CIM) to normalize the field names and speed up the data modeling process.

Known False Positives

Administrator may modify or delete firewall configuration.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
36.0 60 60 A $process_name$ deleted a firewall configuration on $dest$

: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: 1