Detection rules › Splunk

Windows Mshta Execution In Registry

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
Teoderick Contreras, Splunk
Source
github.com/splunk/security_content

The following analytic detects the execution of mshta.exe via registry entries to run malicious scripts. It leverages registry activity logs to identify entries containing "mshta," "javascript," "vbscript," or "WScript.Shell." This behavior is significant as it indicates potential fileless malware, such as Kovter, which uses encoded scripts in the registry to persist and execute without files. If confirmed malicious, this activity could allow attackers to maintain persistence, execute arbitrary code, and evade traditional file-based detection methods, posing a significant threat to system integrity and security.

MITRE ATT&CK coverage

Event coverage

ProviderEventTitle
SysmonEvent ID 13RegistryEvent (Value Set)

Rule body splunk

name: Windows Mshta Execution In Registry
id: e13ceade-b673-4d34-adc4-4d9c01729753
version: 12
creation_date: '2022-10-14'
modification_date: '2026-05-13'
author: Teoderick Contreras, Splunk
status: production
type: TTP
description: The following analytic detects the execution of mshta.exe via registry entries to run malicious scripts. It leverages registry activity logs to identify entries containing "mshta," "javascript," "vbscript," or "WScript.Shell." This behavior is significant as it indicates potential fileless malware, such as Kovter, which uses encoded scripts in the registry to persist and execute without files. If confirmed malicious, this activity could allow attackers to maintain persistence, execute arbitrary code, and evade traditional file-based detection methods, posing a significant threat to system integrity and security.
data_source:
    - Sysmon EventID 13
search: |-
    | tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Registry
      WHERE Registry.registry_value_data = "*mshta*"
        OR
        Registry.registry_value_data IN ("*javascript:*", "*vbscript:*","*WScript.Shell*")
      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_mshta_execution_in_registry_filter`
how_to_implement: To successfully implement this search, you must be ingesting data that records registry activity from your hosts to populate the endpoint data model in the registry node. This is typically populated via endpoint detection-and-response product, such as Carbon Black or endpoint data sources, such as Sysmon. The data used for this search is typically generated via logs that report reads and writes to the registry.
known_false_positives: No false positives have been identified at this time.
references:
    - https://redcanary.com/threat-detection-report/techniques/mshta/
    - https://learn.microsoft.com/en-us/microsoft-365/security/intelligence/fileless-threats?view=o365-worldwide
drilldown_searches:
    - name: View the detection results for - "$dest$" and "$user$"
      search: '%original_detection_search% | search  dest = "$dest$" user = "$user$"'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
    - name: View risk events for the last 7 days for - "$dest$" and "$user$"
      search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$dest$", "$user$") | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`'
      earliest_offset: 7d
      latest_offset: "0"
finding:
    title: A registry $registry_path$ contains mshta $registry_value_data$ on $dest$
    entity:
        field: user
        type: user
        score: 50
intermediate_findings:
    entities:
        - field: dest
          type: system
          score: 50
          message: A registry $registry_path$ contains mshta $registry_value_data$ on $dest$
analytic_story:
    - Suspicious Windows Registry Activities
    - Windows Persistence Techniques
asset_type: Endpoint
mitre_attack_id:
    - T1218.005
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: endpoint
security_domain: endpoint
tests:
    - name: True Positive Test
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1218.005/mshta_in_registry/sysmon3.log
          source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
          sourcetype: XmlWinEventLog
      test_type: unit

Stages and Predicates

Stage 1: tstats

| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Registry
  WHERE Registry.registry_value_data = "*mshta*"
    OR
    Registry.registry_value_data IN ("*javascript:*", "*vbscript:*","*WScript.Shell*")
  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_mshta_execution_in_registry_filter`

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
Registry.registry_value_dataeq
  • "*mshta*" corpus 5 (sigma 4, splunk 1)
Registry.registry_value_datain
  • "*WScript.Shell*"
  • "*javascript:*"
  • "*vbscript:*"