Block Flash control with the Office COM kill bit (CLSID 70, 16.0)
The `Compatibility Flags` DWORD with value data `1024` (`0x00000400`) sets the Office COM kill bit for CLSID `{D27CDB70-AE6D-11CF-96B8-444553540000}`.
since 0.9.8.11
Purpose
Show registry keys (1)
HKLM\SOFTWARE\Microsoft\Office\16.0\Common\COM Compatibility\{D27CDB70-AE6D-11CF-96B8-444553540000}\Compatibility Flags
The Compatibility Flags DWORD with value data 1024 (0x00000400) sets the Office COM kill bit for CLSID {D27CDB70-AE6D-11CF-96B8-444553540000}. Microsoft identifies the associated ActiveX control as Macromedia Flash Factory Object.
The kill bit prevents Office from activating this COM object. Office documents therefore cannot load the affected Flash control as an embedded or linked object.
Notes
Additional effects
In Office versions containing the updated COM kill bit functionality, blocking is not limited to objects embedded in or linked from documents. Activation of the specified COM object is blocked throughout an Office process, including attempts made through add-ins or other code running inside Office.
Security
Blocking the control reduces the Office attack surface by preventing this Flash-based ActiveX component from executing inside Office processes. Document content therefore cannot activate the blocked COM object.
The Office COM kill bit list operates independently of the Internet Explorer ActiveX kill bit list. Where the two lists conflict, the Office setting takes precedence inside Office.
Possible side effects
Documents, templates, macros, or add-ins that depend on this specific Flash control can no longer use its content or functionality. Depending on the application and activation method, the object might not be displayed, might not be insertable, or might cause an error when loaded.
This entry does not automatically block other Flash COM classes. In particular, the Shockwave Flash Object also listed by Microsoft uses the different CLSID {D27CDB6E-AE6D-11CF-96B8-444553540000}.
Notes
The specified path belongs to the Office 16.0 version branch. For 32-bit Office running on 64-bit Windows, Microsoft documents the corresponding registry location under HKLM\SOFTWARE\Wow6432Node\Microsoft\Office\16.0\...; the value in the non-redirected path described here therefore does not cover that configuration.
An additional ActivationFilterOverride DWORD set to 1 under the same CLSID key would limit blocking to linking and embedding scenarios. Without that separate override, the updated Office COM kill bit blocks all activation attempts from within Office.
Microsoft currently includes Macromedia Flash Factory Object in its list of controls blocked from activation by default. Microsoft also states that this default list is a snapshot and may change.
Microsoft documentation
Microsoft Support: Security Settings for COM objects in Office