Detection rules › Splunk

Windows Modify Registry Utilize ProgIDs

Status
production
Severity
low
Group by
TargetObject, computer_name, details, event_type, process_guid, process_id, registry_hive, registry_path, registry_status, registry_value_name, registry_value_type, user, vendor_product
Author
Teoderick Contreras, Splunk
Source
github.com/splunk/security_content

The following analytic detects modifications to the Windows Registry specifically targeting Programmatic Identifier associations to bypass User Account Control (UAC) Windows OS feature. ValleyRAT may create or alter registry entries to 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.

Known false positives

  • No false positives have been identified at this time.

MITRE ATT&CK coverage

TacticTechniques
Persistence
Defense Impairment

Telemetry coverage

Rule body

name: Windows Modify Registry Utilize ProgIDs
id: 64fa82dd-fd11-472a-9e94-c221fffa591d
version: 11
creation_date: '2024-09-18'
modification_date: '2026-05-13'
author: Teoderick Contreras, Splunk
status: production
type: Anomaly
description: The following analytic detects modifications to the Windows Registry specifically targeting Programmatic Identifier associations to bypass User Account Control (UAC) Windows OS feature. ValleyRAT may create or alter registry entries to 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.
data_source:
    - Sysmon EventID 13
search: '| tstats `security_content_summariesonly` count FROM datamodel=Endpoint.Registry WHERE Registry.registry_path= "*\\ms-settings\\CurVer\\(Default)" by Registry.action Registry.dest Registry.process_guid Registry.process_id Registry.registry_hive Registry.registry_path Registry.registry_key_name Registry.registry_value_data Registry.registry_value_name Registry.registry_value_type Registry.status Registry.user Registry.vendor_product | `drop_dm_object_name(Registry)` | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `windows_modify_registry_utilize_progids_filter`'
how_to_implement: 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 official Sysmon TA. https://splunkbase.splunk.com/app/5709
known_false_positives: No false positives have been identified at this time.
references:
    - https://www.proofpoint.com/us/blog/threat-insight/chinese-malware-appears-earnest-across-cybercrime-threat-landscape
    - https://www.fortinet.com/blog/threat-research/valleyrat-campaign-targeting-chinese-speakers
    - https://v3ded.github.io/redteam/utilizing-programmatic-identifiers-progids-for-uac-bypasses
intermediate_findings:
    entities:
        - field: user
          type: user
          score: 20
          message: A possible ValleyRAT Registry modification in [$dest$].
        - field: dest
          type: system
          score: 20
          message: A possible ValleyRAT Registry modification in [$dest$].
analytic_story:
    - ValleyRAT
asset_type: Endpoint
mitre_attack_id:
    - T1112
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: endpoint
security_domain: endpoint

Stages and Predicates

Stage 1: tstats

| tstats `security_content_summariesonly` count FROM datamodel=Endpoint.Registry WHERE Registry.registry_path= "*\\ms-settings\\CurVer\\(Default)" by Registry.action Registry.dest Registry.process_guid Registry.process_id Registry.registry_hive Registry.registry_path Registry.registry_key_name Registry.registry_value_data Registry.registry_value_name Registry.registry_value_type Registry.status Registry.user Registry.vendor_product

Stage 2: search

| `drop_dm_object_name(Registry)`

Stage 3: search

| `security_content_ctime(firstTime)`

Stage 4: search

| `security_content_ctime(lastTime)`

Stage 5: search

| `windows_modify_registry_utilize_progids_filter`

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
Registry.registry_patheq
  • "*\\ms-settings\\CurVer\\(Default)"
field:"registry_path" kind:eq