Windows SpeechRuntime Suspicious Child Process

name: Windows SpeechRuntime Suspicious Child Process
id: f7bb956f-b956-42a5-8c2c-ff9cdbbf7526
version: 5
creation_date: '2025-08-27'
modification_date: '2026-05-13'
author: Raven Tait, Splunk
status: production
type: TTP
description: SpeechRuntime is vulnerable to an attack that allows a user to run code on another user's session remotely and stealthily by exploiting a Windows COM class. When this class is invoked, it launches SpeechRuntime.exe in the context of the currently logged-on user. Because this COM class is susceptible to COM Hijacking, the attacker can alter the registry remotely to point to a malicious DLL. By dropping that DLL on the target system (e.g., via SMB) and triggering the COM object, the attacker causes the malicious DLL to load into SpeechRuntime.exe and executing under the user's context. This detection identifies suspicious child processes of SpeechRuntime.exe that could indicate abuse of this vulnerability.
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="*SpeechRuntime.exe*"
        )
        Processes.process IN ("*cmd.exe*","*powershell.exe*","*rundll32.exe*","*bitsadmin.exe*","*wmic.exe*","*cscript.exe*")
      BY Processes.dest Processes.user Processes.original_file_name
         Processes.parent_process Processes.process_name Processes.process
         Processes.process_id Processes.parent_process_id Processes.parent_process_name
         action parent_process_exec parent_process_guid
         parent_process_path process_exec process_guid
         process_hash process_integrity_level process_path
         user_id vendor_product
    | `drop_dm_object_name(Processes)`
    | `security_content_ctime(firstTime)`
    | `security_content_ctime(lastTime)`
    | `windows_speechruntime_suspicious_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: This process should normally never be spawning these child processes.
references:
    - https://github.com/rtecCyberSec/SpeechRuntimeMove
finding:
    title: Possible Lateral Movement on $dest$ by abusing SpeechRuntime.
    entity:
        field: dest
        type: system
        score: 50
threat_objects:
    - field: parent_process_name
      type: parent_process_name
analytic_story:
    - Active Directory Lateral Movement
    - Compromised Windows Host
asset_type: Endpoint
mitre_attack_id:
    - T1021.003
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: endpoint
security_domain: endpoint