Mar 07 2023 04:46 AM
We have implemented the WDAC Policy. It works so far, but I have a problem with two drivers. They are things I can't solve. It is a smart card reader by Reiner (file cjusb.sys). This file is signed, but it seems that Windows Policy control doesn’t accept or doesn’t understand this signature.
I have similar problems with Bloomberg application files, but after I signed them with my signature ist works without problems. But this file is blocked by WDAC even if I signed it.
Probably somebody confronted with similar problems, can give me advice for additional debugging or a clue how I can solve this issue.
Mar 07 2023 10:11 AM
Mar 08 2023 01:24 AM - edited Mar 08 2023 01:31 AM
I have found a reason why Windows Defender acts in this way. If a driver KMDF specified and non WHQL certified it will be blocked by defender regardless if it is signed. I talked yesterday with the provider and he gave me a UMDF driver. Now everything works.
For Bloomberg we have written a program which checks files against Bloomberg certificates and re-signs them if they qualify given criteria. Process takes about 3min and the user does accept this. After resigning Bloomberg works as expected.
I haven't opened any directories because it is difficult to monitor them all...