The attributes are inherited from the folder in which the .ocx is stored. If it is a secured folder such as
windows/system32/
then the files in that folder will have the same security attributes applied.
This means to remove the file the application needs to be executed by an account or group with the necessary rights to remove the .ocx.
The .ocx cannot be removed if it is in use.
[Update]
You may need to unregister the ocx first. MSDN link:
http://support.microsoft.com/kb/173091[
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