Device Guard in Windows 10 Gold, 1511, 1607, 1703, and 1709, Windows Server 2016, and Windows Server, version 1709 allows an attacker to make an unsigned file appear to be signed, due to a security feature bypass, aka "Device Guard Security Feature Bypass Vulnerability".
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2017-11830