Techniques
Sample rules
Windows SpeechRuntime COM Hijacking DLL Load
- source: splunk
- technicques:
- T1021.003
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 DLL loads by SpeechRuntime.exe from outside the expected locations.
Detection logic
`sysmon` EventCode=7 Image="*SpeechRuntime.exe"
| eval image_loaded_lower = lower(ImageLoaded)
| search NOT image_loaded_lower="*system32*"
| fillnull
| stats count min(_time) as firstTime max(_time) as lastTime by Image ImageLoaded dest loaded_file loaded_file_path original_file_name parent_process_name parent_process_guid process_exec process_guid process_hash process_id process_name process_path service_dll_signature_exists service_dll_signature_verified signature signature_id user_id vendor_product
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `windows_speechruntime_com_hijacking_dll_load_filter`