Anatomy of a WHQL-Signed Windows Filtering Platform (WFP) Kernel-Resident Network Backdoor

A signed kernel driver is one of the most powerful execution primitives available on Windows. Once loaded, it operates with unrestricted access to memory, processes, filesystems, and network traffic. wskmon.sys takes full advantage of that position. Rather than acting as a simple kernel implant, it implements a complete network-accessible backdoor inside a trusted, WHQL-signed driver. Overview wskmon.sys is a 64-bit Windows kernel-mode driver that acts as a fully-featured…