IExtensionValidation interface

For Internet Explorer 11, specifies an interface the anti-malware vendors can implement. Vendors that register support for this interface may be called by IE11 to validate that an ActiveX control is safe to instantiate.


The IExtensionValidation interface inherits from the IUnknown interface. IExtensionValidation also has these types of members:

  • Methods


The IExtensionValidation interface has these methods.

Method Description

IE11 will call this method to determine the name of the security software to display on the blocking dialog.


IE11 will call this method prior to instantiating an ActiveX control.


IExtensionValidation provides two methods. The Validate method allows an anti-malware vendor the opportunity to use page context, such as the top-level IHTMLDocument2, to help determine whether an Activex control, identified by its registered GUID, is safe to instantiate.

To register to use this interface, security software need to first register a DLL component as an in-process server that implements the IExtensionValidation interface. To register to use this interface, you will need to write the following registry key as a part of your application installation:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\Extension Validation\{CLSID}

Under this component, you will need to define an inProcServer32 registry key. Here the {CLSID} is the CLSID for your security product found under HKEY_CLASSES_ROOT\CLSID\

Note As a part of your uninstallation process, you will need to make sure that you remove this registry key.

IE11 calls the IExtensionValidation interface with context on the ActiveX control and web page content to check with the registered security product whether it is safe or not to load an ActiveX control. IE11 will only ask one security product to make this determination. For IE11 to call a security product using the IExtensionValidation interface, the security product must implement all IExtensionValidation methods. Otherwise, IE11 will not call the security product.


Minimum supported client

Windows 7

Minimum supported server

Windows Server 2008 R2