EDR Killing

BYOVD (Bring Your Own Vulnerable Driver) attacks have become a standard component of ransomware operations, allowing attackers to exploit signed kernel drivers for kernel-level access and subsequently disable AV/EDR products. The technique involves dropping a legitimate but vulnerable signed driver, loading it via a Windows service, and sending crafted IOCTL commands to terminate, blind, or strip privileges from security software. Microsoft's kernel hardening features and Vulnerable Driver Blocklist provide insufficient protection, as data-only kernel attacks bypass hardening and the blocklist has significant update lag. Behavioral monitoring of anomalous driver IOCTL interactions is the most effective defensive approach, as it is driver-agnostic and does not depend on prior driver identification.