Detection rules › Splunk

Suspicious mshta child process

Status
production
Severity
medium
Group by
IntegrityLevel, command_line, computer_name, event_action, original_file_name, parent_command_line, parent_process_guid, parent_process_id, parent_process_name, process_guid, process_hash, process_id, process_name, user, user_id, vendor_product
Author
Michael Haag, Teoderick Contreras Splunk
Source
github.com/splunk/security_content

The following analytic identifies child processes spawned from "mshta.exe". It leverages data from Endpoint Detection and Response (EDR) agents, focusing on specific child processes like "powershell.exe" and "cmd.exe". This activity is significant because "mshta.exe" is often exploited by attackers to execute malicious scripts or commands. If confirmed malicious, this behavior could allow an attacker to execute arbitrary code, escalate privileges, or maintain persistence within the environment. Monitoring this activity helps in early detection of potential threats leveraging "mshta.exe" for malicious purposes.

Known false positives

  • Although unlikely, some legitimate applications may exhibit this behavior, triggering a false positive.

MITRE ATT&CK coverage

Telemetry coverage

Rule body

name: Suspicious mshta child process
id: 60023bb6-5500-11eb-ae93-0242ac130002
version: 15
creation_date: '2021-01-17'
modification_date: '2026-05-13'
author: Michael Haag, Teoderick Contreras Splunk
status: production
type: TTP
description: The following analytic identifies child processes spawned from "mshta.exe". It leverages data from Endpoint Detection and Response (EDR) agents, focusing on specific child processes like "powershell.exe" and "cmd.exe". This activity is significant because "mshta.exe" is often exploited by attackers to execute malicious scripts or commands. If confirmed malicious, this behavior could allow an attacker to execute arbitrary code, escalate privileges, or maintain persistence within the environment. Monitoring this activity helps in early detection of potential threats leveraging "mshta.exe" for malicious purposes.
data_source:
    - Sysmon EventID 1
    - Windows Event Log Security 4688
    - CrowdStrike ProcessRollup2
search: |-
    | tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Processes
      WHERE Processes.parent_process_name=mshta.exe
        AND
        Processes.process_name IN ("powershell.exe","colorcpl.exe", "msbuild.exe", "microsoft.workflow.compiler.exe", "searchprotocolhost.exe", "scrcons.exe", "cscript.exe", "wscript.exe", "cmd.exe", "bitsadmin.exe")
      BY Processes.action Processes.dest Processes.original_file_name
         Processes.parent_process Processes.parent_process_exec Processes.parent_process_guid
         Processes.parent_process_id Processes.parent_process_name Processes.parent_process_path
         Processes.process Processes.process_exec Processes.process_guid
         Processes.process_hash Processes.process_id Processes.process_integrity_level
         Processes.process_name Processes.process_path Processes.user
         Processes.user_id Processes.vendor_product
    | `drop_dm_object_name(Processes)`
    | `security_content_ctime(firstTime)`
    | `security_content_ctime(lastTime)`
    | `suspicious_mshta_child_process_filter`
how_to_implement: The detection is based on data that originates from Endpoint Detection and Response (EDR) agents. These agents are designed to provide security-related telemetry from the endpoints where the agent is installed. To implement this search, you must ingest logs that contain the process GUID, process name, and parent process. Additionally, you must ingest complete command-line executions. These logs must be processed using the appropriate Splunk Technology Add-ons that are specific to the EDR product. The logs must also be mapped to the `Processes` node of the `Endpoint` data model. Use the Splunk Common Information Model (CIM) to normalize the field names and speed up the data modeling process.
known_false_positives: Although unlikely, some legitimate applications may exhibit this behavior, triggering a false positive.
references:
    - https://github.com/redcanaryco/AtomicTestHarnesses
    - https://redcanary.com/blog/introducing-atomictestharnesses/
finding:
    title: Suspicious mshta child process $process_name$ detected on host $dest$ by user $user$.
    entity:
        field: user
        type: user
        score: 50
intermediate_findings:
    entities:
        - field: dest
          type: system
          score: 50
          message: Suspicious mshta child process $process_name$ detected on host $dest$ by user $user$.
threat_objects:
    - field: process_name
      type: process_name
analytic_story:
    - Suspicious MSHTA Activity
    - Living Off The Land
    - Lumma Stealer
    - MuddyWater
asset_type: Endpoint
mitre_attack_id:
    - T1218.005
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: endpoint
security_domain: endpoint

Stages and Predicates

Stage 1: tstats

| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Processes
  WHERE Processes.parent_process_name=mshta.exe
    AND
    Processes.process_name IN ("powershell.exe","colorcpl.exe", "msbuild.exe", "microsoft.workflow.compiler.exe", "searchprotocolhost.exe", "scrcons.exe", "cscript.exe", "wscript.exe", "cmd.exe", "bitsadmin.exe")
  BY Processes.action Processes.dest Processes.original_file_name
     Processes.parent_process Processes.parent_process_exec Processes.parent_process_guid
     Processes.parent_process_id Processes.parent_process_name Processes.parent_process_path
     Processes.process Processes.process_exec Processes.process_guid
     Processes.process_hash Processes.process_id Processes.process_integrity_level
     Processes.process_name Processes.process_path Processes.user
     Processes.user_id Processes.vendor_product

Stage 2: search

| `drop_dm_object_name(Processes)`

Stage 3: search

| `security_content_ctime(firstTime)`

Stage 4: search

| `security_content_ctime(lastTime)`

Stage 5: search

| `suspicious_mshta_child_process_filter`

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
Processes.parent_process_nameeq
  • "mshta.exe" corpus 24 (elastic 22, splunk 2)
field:"parent_process_name" kind:eq
Processes.process_namein
  • "bitsadmin.exe" corpus 23 (elastic 21, splunk 2)
  • "cmd.exe" corpus 121 (elastic 92, splunk 29)
  • "colorcpl.exe"
  • "cscript.exe" corpus 67 (elastic 65, splunk 2)
  • "microsoft.workflow.compiler.exe" corpus 12 (elastic 11, splunk 1)
  • "msbuild.exe" corpus 39 (elastic 36, splunk 3)
  • "powershell.exe" corpus 184 (elastic 140, splunk 44)
  • "scrcons.exe"
  • "searchprotocolhost.exe" corpus 6 (elastic 4, splunk 2)
  • "wscript.exe" corpus 83 (elastic 82, splunk 1)
field:"process_name" kind:in