All valid points. I think it should be possible, at least for Microsoft DLLs, to specify a flag that you are willing to load only those signed by Microsoft. A m

All valid points. I think it should be possible, at least for Microsoft DLLs, to specify a flag that you are willing to load only those signed by Microsoft. A malicious version.dll wouldn't probably have a Microsoft signature. The signature verification would be done by the OS and thus would be future-proof. Even a OS-local whitelist for exemptions could work, where an admin could add some unsigned DLL hashes to the list that would still load. None of the downloaded malicious DLL files would pass this test.