Detection: Windows Modify Registry Utilize ProgIDs

Updated Date: 2024-09-18 ID: 64fa82dd-fd11-472a-9e94-c221fffa591d Author: Teoderick Contreras, Splunk Type: Anomaly Product: Splunk Enterprise Security

Description

The following analytic detects modifications to the Windows Registry specifically targeting Programmatic Identifier associations to bypassed User Account Control (UAC) Windows OS feature. ValleyRAT may create or alter registry entries to a targetted progIDs like .pwn files with malicious processes, allowing it to execute harmful scripts or commands when these files are opened. By monitoring for unusual changes in registry keys linked to ProgIDs, this detection enables security analysts to identify potential threats like ValleyRAT execution attempts. Early detection of these modifications helps mitigate unauthorized execution and prevents further exploitation of the system.

1
2| tstats `security_content_summariesonly` count FROM datamodel=Endpoint.Registry WHERE Registry.registry_path= "*\\ms-settings\\CurVer\\(Default)" BY Registry.dest Registry.user Registry.registry_path Registry.registry_key_name Registry.registry_value_name Registry.registry_value_data Registry.process_guid 
3| `drop_dm_object_name(Registry)` 
4| `security_content_ctime(firstTime)` 
5| `security_content_ctime(lastTime)` 
6| `windows_modify_registry_utilize_progids_filter`

Data Source

Name Platform Sourcetype Source Supported App
N/A N/A N/A N/A N/A

Macros Used

Name Value
security_content_ctime convert timeformat="%Y-%m-%dT%H:%M:%S" ctime($field$)
windows_modify_registry_utilize_progids_filter search *
windows_modify_registry_utilize_progids_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
T1112 Modify Registry Defense Evasion
KillChainPhase.EXPLOITAITON
NistCategory.DE_AE
Cis18Value.CIS_10
APT19
APT32
APT38
APT41
Blue Mockingbird
Dragonfly
Earth Lusca
Ember Bear
FIN8
Gamaredon Group
Gorgon Group
Kimsuky
LuminousMoth
Magic Hound
Patchwork
Silence
TA505
Threat Group-3390
Turla
Wizard Spider

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 Risk Event True
This configuration file applies to all detections of type anomaly. These detections will use Risk Based Alerting.

Implementation

To successfully implement this search, you need to be ingesting logs with the registry value name, registry path, and registry value data from your endpoints. If you are using Sysmon, you must have at least version 2.0 of the offical Sysmon TA. https://splunkbase.splunk.com/app/5709

Known False Positives

unknown

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message Risk Score Impact Confidence
A possible ValleyRAT Registry modification in [$dest$]. 49 70 70
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

References

Detection Testing

Test Type Status Dataset Source Sourcetype
Validation ✅ Passing N/A N/A N/A
Unit ✅ Passing Dataset XmlWinEventLog:Microsoft-Windows-Sysmon/Operational xmlwineventlog
Integration ✅ Passing Dataset XmlWinEventLog:Microsoft-Windows-Sysmon/Operational xmlwineventlog

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: 1