Summary
Learn about the effect of the Microsoft Security (MS) Bulletin MS13-098 on Endpoint Application Control (TMEAC).
Details
After installing and activating the MS Security Bulletin MS13-098 update, the AC agent will not be able to detect applications that run specifically crafted, signed PE files if the Certificate Attributes rule method is used.
If MS Windows identifies the content in the PE file does not conform with the Authenticode specification, the security update for MS Windows will consider the PE file as unsigned. If the signature is removed then the Certificate Attributes rule method will not match the unsigned PE files to any attributes.
To resolve the issue:
On systems where the security update has been applied, the specially crafted PE file will no longer have a digital signature. To validate if a digital signature exists on the PE file, right-click on the PE file then go to File Properties.
If the signature no longer exists, specify another rule method to detect the specially crafted, signed PE file. One of the rule methods that you can specify is file signature (SHA-1) or patch expressions.