Windows Modify Registry LongPathsEnabled

Description

The following analytic identifies a suspicious registry modification of Windows long path enable configuration. This technique was being abused by several adversaries, malware like BlackByte to enable long file path support in the operating system. By default, Windows has a limitation on the maximum length of a file path, which is set to 260 characters. Enabling the LongPathsEnabled setting allows you to work with file paths longer than 260 characters.

Type: Anomaly
Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
Datamodel: Endpoint
Last Updated: 2023-07-10
Author: Teoderick Contreras, Splunk
ID: 36f9626c-4272-4808-aadd-267acce681c0

Annotations

ATT&CK

ID	Technique	Tactic
T1112	Modify Registry	Defense Evasion

Kill Chain Phase

Exploitation

NIST

DE.AE

CIS20

CIS 10

CVE

Search

| tstats `security_content_summariesonly` count FROM datamodel=Endpoint.Registry WHERE (Registry.registry_path= "*\\CurrentControlSet\\Control\\FileSystem\\LongPathsEnabled" Registry.registry_value_data = "0x00000001") BY _time span=1h Registry.registry_path Registry.registry_key_name Registry.registry_value_name Registry.registry_value_data Registry.process_guid Registry.dest 
| `drop_dm_object_name(Registry)` 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `windows_modify_registry_longpathsenabled_filter`

Macros

The SPL above uses the following Macros:

windows_modify_registry_longpathsenabled_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
Registry.registry_key_name
Registry.registry_path
Registry.user
Registry.dest
Registry.registry_value_name
Registry.action
Registry.registry_value_data

How To Implement

To successfully implement this search you need to be ingesting information on process that include the name of the process responsible for the changes from your endpoints into the Endpoint datamodel in the Registry node. Also make sure that this registry was included in your config files ex. sysmon config to be monitored.

Known False Positives

Administrators may enable or disable this feature that may cause some false positive.

Associated Analytic Story

BlackByte Ransomware

RBA

Risk Score	Impact	Confidence	Message
16.0	40	40	A registry modification in Windows LongPathEnable configuration on $dest$

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

https://www.microsoft.com/en-us/security/blog/2023/07/06/the-five-day-job-a-blackbyte-ransomware-intrusion-case-study/

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

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