Detection rules › Splunk
Windows SpeechRuntime COM Hijacking DLL Load
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.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Lateral Movement | T1021.003 Remote Services: Distributed Component Object Model |
Event coverage
| Provider | Event ID | Title |
|---|---|---|
| Sysmon | 7 | Image loaded |
Stages and Predicates
Stage 1: search
search EventCode=7 Image="*SpeechRuntime.exe"
Stage 2: eval
eval ... using (ImageLoaded)
Stage 3: search
search NOT image_loaded_lower="*system32*"
Stage 4: fillnull
fillnull
Stage 5: stats
stats 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
Stage 6: search
search
Stage 7: search
search
Stage 8: search
search `macro`
Exclusions
Top-level NOT(...) conjuncts — predicates this rule actively suppresses.
| Stage | Field | Kind | Excluded values |
|---|---|---|---|
| 1 | image_loaded_lower | eq | "*system32*" |
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.
| Field | Kind | Values |
|---|---|---|
EventCode | eq |
|
Image | eq |
|
Neighbors
Broader alternatives (more inclusive than this rule)
These rules match a superset of what this rule catches. They cover the same events plus more. Use them if you want wider coverage and can absorb more false positives.
- Windows Remote Access Software BRC4 Loaded Dll (drops 1 filter this rule applies)