Detection: Windows SpeechRuntime Suspicious Child Process

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.

Search

1
2| 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 
3| `drop_dm_object_name(Processes)` 
4| `security_content_ctime(firstTime)` 
5| `security_content_ctime(lastTime)`
6| `windows_speechruntime_suspicious_child_process_filter`

Data Source

Name	Platform	Sourcetype	Source
CrowdStrike ProcessRollup2	N/A	'crowdstrike:events:sensor'	'crowdstrike'
Sysmon EventID 1	Windows	'XmlWinEventLog'	'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational'
Windows Event Log Security 4688	Windows	'XmlWinEventLog'	'XmlWinEventLog:Security'

Macros Used

Annotations

Default Configuration

This detection is configured by default in Splunk Enterprise Security to run with the following settings:

Implementation

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.

Associated Analytic Story

• Active Directory Lateral Movement

• Compromised Windows Host

Risk Based Analytics (RBA)

Risk Message:

Possible Lateral Movement on $dest$ by abusing SpeechRuntime.

References

• https://github.com/rtecCyberSec/SpeechRuntimeMove

Detection Testing

Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

Source: GitHub | Version: 1