Adversaries may establish persistence by executing malicious content triggered by hijacked references to Component Object Model (COM) objects. COM is a system within Windows to enable interaction between software components through the operating system.[1] References to various COM objects are stored in the Registry.
Adversaries may use the COM system to insert malicious code that can be executed in place of legitimate software through hijacking the COM references and relationships as a means for persistence. Hijacking a COM object requires a change in the Registry to replace a reference to a legitimate system component which may cause that component to not work when executed. When that system component is executed through normal system operation the adversary's code will be executed instead.[2] An adversary is likely to hijack objects that are used frequently enough to maintain a consistent level of persistence, but are unlikely to break noticeable functionality within the system as to avoid system instability that could lead to detection.
One variation of COM hijacking involves abusing Type Libraries (TypeLibs), which provide metadata about COM objects, such as their interfaces and methods. Adversaries may modify Registry keys associated with TypeLibs to redirect legitimate COM object functionality to malicious scripts or payloads. Unlike traditional COM hijacking, which commonly uses local DLLs, this variation may leverage the "script:" moniker to execute remote scripts hosted on external servers.[3] This approach enables stealthy execution of code while maintaining persistence, as the remote payload would be automatically downloaded whenever the hijacked COM object is accessed.
| ID | Name | Description |
|---|---|---|
| S0045 | ADVSTORESHELL | Some variants ofADVSTORESHELL achieve persistence by registering the payload as a Shell Icon Overlay handler COM object.[4] |
| G0007 | APT28 | APT28 has used COM hijacking for persistence by replacing the legitimate |
| S0127 | BBSRAT | BBSRAT has been seen persisting via COM hijacking through replacement of the COM object for MruPidlList |
| S0126 | ComRAT | ComRAT samples have been seen which hijack COM objects for persistence by replacing the path to shell32.dll in registry location |
| S0679 | Ferocious | Ferocious can use COM hijacking to establish persistence.[9] |
| S0044 | JHUHUGIT | JHUHUGIT has used COM hijacking to establish persistence by hijacking a class named MMDeviceEnumerator and also by registering the payload as a Shell Icon Overlay handler COM object ({3543619C-D563-43f7-95EA-4DA7E1CC396A}).[5][10] |
| S0356 | KONNI | KONNI has modified ComSysApp service to load the malicious DLL payload.[11] |
| S0256 | Mosquito | |
| S1050 | PcShare | PcShare has created the |
| S0692 | SILENTTRINITY | SILENTTRINITY can add a CLSID key for payload execution through |
| S1064 | SVCReady | SVCReady has created the |
| S0670 | WarzoneRAT | WarzoneRAT can perform COM hijacking by setting the path to itself to the |
This type of attack technique cannot be easily mitigated with preventive controls since it is based on the abuse of system features.
| ID | Name | Analytic ID | Analytic Description |
|---|---|---|---|
| DET0481 | Windows COM Hijacking Detection via Registry and DLL Load Correlation | AN1323 | Correlate suspicious registry modifications to known COM object CLSIDs with subsequent DLL loads or unexpected binary execution paths. Detect placement of COM CLSID entries under HKEY_CURRENT_USER\Software\Classes\CLSID\ overriding default HKLM paths. Flag anomalous DLL loads traced back to hijacked COM registry changes. |