In the last 3 months we have seen a lot of machines compromised by Uroburos (a kernel-mode rootkit that specifically targets Windows 7 64-bit). Curiosity lead me to start analyzing the code for Kernel Patch Protection on Windows 8.1. We will take a glance at its current implementation on that operating system and find out why the kernel Patch Protection modifications on Windows 7 dont work on the Windows 8. The implementation of Patchguard has slightly changed between versions of Windows.”]
Source: https://blog.talosintelligence.com/2014/08/the-windows-81-kernel-patch-protection.html