Detection rules › Splunk

Windows Snake Malware Registry Modification wav OpenWithProgIds

Status
production
Severity
medium
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
Michael Haag, Splunk
Source
github.com/splunk/security_content

The following analytic identifies modifications to the registry path .wav\OpenWithProgIds, associated with the Snake Malware campaign. It leverages data from the Endpoint.Registry datamodel to detect changes in this specific registry location. This activity is significant because Snake's WerFault.exe uses this registry path to decrypt an encrypted blob containing critical components like the AES key, IV, and paths for its kernel driver and loader. If confirmed malicious, this could allow the attacker to load and execute Snake's kernel driver, leading to potential system compromise and persistent access.

Known false positives

  • False positives may be present and will require tuning based on program Ids in large organizations.

MITRE ATT&CK coverage

TacticTechniques
Persistence
Defense Impairment

Telemetry coverage

Rule body

name: Windows Snake Malware Registry Modification wav OpenWithProgIds
id: 13cf8b79-805d-443c-bf52-f55bd7610dfd
version: 11
creation_date: '2023-05-11'
modification_date: '2026-05-13'
author: Michael Haag, Splunk
status: production
type: TTP
description: The following analytic identifies modifications to the registry path .wav\\OpenWithProgIds, associated with the Snake Malware campaign. It leverages data from the Endpoint.Registry datamodel to detect changes in this specific registry location. This activity is significant because Snake's WerFault.exe uses this registry path to decrypt an encrypted blob containing critical components like the AES key, IV, and paths for its kernel driver and loader. If confirmed malicious, this could allow the attacker to load and execute Snake's kernel driver, leading to potential system compromise and persistent access.
data_source:
    - Sysmon EventID 13
search: '| tstats `security_content_summariesonly` count values(Registry.registry_key_name) as registry_key_name values(Registry.registry_path) as registry_path min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Registry where Registry.registry_path="*\\.wav\\OpenWithProgIds\\*" 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 | `security_content_ctime(lastTime)` | `security_content_ctime(firstTime)` | `drop_dm_object_name(Registry)` | `windows_snake_malware_registry_modification_wav_openwithprogids_filter`'
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. In addition, confirm the latest CIM App 4.20 or higher is installed and the latest TA for the endpoint product.
known_false_positives: False positives may be present and will require tuning based on program Ids in large organizations.
references:
    - https://media.defense.gov/2023/May/09/2003218554/-1/-1/0/JOINT_CSA_HUNTING_RU_INTEL_SNAKE_MALWARE_20230509.PDF
finding:
    title: A registry modification related to Snake Malware has been identified on $dest$.
    entity:
        field: dest
        type: system
        score: 50
analytic_story:
    - Snake Malware
asset_type: Endpoint
atomic_guid:
    - 8318ad20-0488-4a64-98f4-72525a012f6b
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 values(Registry.registry_key_name) as registry_key_name values(Registry.registry_path) as registry_path min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Registry where Registry.registry_path="*\\.wav\\OpenWithProgIds\\*" 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

| `security_content_ctime(lastTime)`

Stage 3: search

| `security_content_ctime(firstTime)`

Stage 4: search

| `drop_dm_object_name(Registry)`

Stage 5: search

| `windows_snake_malware_registry_modification_wav_openwithprogids_filter`

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
Registry.registry_patheq
  • "*\\.wav\\OpenWithProgIds\\*"
field:"registry_path" kind:eq