During a high-stakes malware investigation, your team discovered a suspicious device driver on a compromised...

Option C. It could be using kernel patching is the best answer because the scenario describes a suspicious device driver interacting with low-level system resources , which strongly suggests kernel-level rootkit behavior . In CHFI-style malware analysis, rootkits are associated with hiding malicious presence by interfering with operating-system functions at a deep level. Kernel patching allows a rootkit to alter or intercept key kernel structures or behavior, making malicious processes, files, registry artifacts, or network activity harder for standard tools to detect.

This fits the question better than the other options. Process cloaking can occur, but the clue about a driver accessing low-level resources points more directly to a kernel-oriented hiding technique. A zero-day vulnerability may be an entry method, but it is not itself the concealment technique being asked about. Hooking into a legitimate driver is possible in some cases, but kernel patching is the more direct and classic rootkit evasion method when operating at that privileged layer.

Therefore, in the context of a suspicious driver behaving like a rootkit, the most accurate CHFI-aligned answer is kernel patching .