Attackers can load a legitimately signed but vulnerable driver, exploit it from user mode, and obtain the kernel-level capabilities needed to disable endpoint defenses. Ranger prevents this exploitation, including when the driver is not yet present on a blocklist.
A signed driver can still contain an exploitable kernel interface.
A digital signature confirms a driver's publisher and integrity; it does not verify that every privileged operation the driver exposes is secure. If the driver contains a vulnerable interface, an attacker can use it to perform kernel operations that are unavailable to an ordinary user-mode process.
Windows uses digital signatures to verify a driver's publisher and integrity before loading it. A correctly signed driver can still expose a vulnerable interface that allows an attacker-controlled process to perform privileged kernel operations.
The driver may come from a graphics, audio, antivirus, disk, or monitoring product and carry a valid signature. Windows and conventional allowlists recognize it as legitimate software installed through standard mechanisms.
From user mode, the attacker calls the driver's vulnerable interface to perform privileged kernel operations. That capability can be used to terminate security processes, remove callbacks, suppress logging, or prepare the system for an undetected payload.
A BYOVD attack follows a clear sequence: introduce a vulnerable signed driver, load it, exploit the exposed interface, and tamper with endpoint security. Ranger blocks the exploitation attempt before the attacker obtains kernel-level privileges.
After compromising an endpoint through phishing, stolen credentials, or an exposed service, the attacker writes a legitimate but vulnerable driver to the system.
The attacker uses standard installation mechanisms to load the signed driver. Because its signature is valid, the operating system may allow it into the kernel.
An attacker-controlled process calls the driver's vulnerable interface to gain privileged operations that are normally unavailable from user mode.
With kernel-level privileges, the attacker can disable endpoint protection, suppress telemetry, establish persistence, and deploy ransomware or other payloads after security controls are disabled.
Ranger does not depend on a driver being discovered, reported, and added to a blocklist. It prevents the kernel-level exploitation used by BYOVD attacks, including drivers not yet identified as vulnerable.
Ranger evaluates attempts by user-mode processes to access sensitive kernel capabilities, independent of the specific driver name, hash, or public vulnerability record.
It prevents an attacker from using a vulnerable signed driver to obtain the kernel-level privileges needed to tamper with security software or system behavior.
EDR, antivirus, logging, and other endpoint controls remain active, preserving the visibility and response capability the rest of the security stack relies on.
A signature identifies the publisher, while a blocklist identifies drivers already known to be vulnerable. Neither identifies an undisclosed vulnerability. Ranger prevents attempts to obtain privileged kernel capabilities without requiring prior knowledge of the driver.
This protection works alongside existing endpoint security rather than replacing it. Ranger adds kernel-level tamper protection for products such as CrowdStrike, Microsoft Defender, SentinelOne, and others without requiring a separate vulnerable-driver list.
Ranger prevents BYOVD exploitation while preserving the endpoint tools and operational model already in place.
Clear answers about how Ranger handles vulnerable drivers, works with your existing endpoint security, and prevents privileged abuse.
A blocklist can stop drivers that have already been identified and included in an update. Ranger prevents vulnerable-driver exploitation even when a driver is unknown, newly disclosed, or not yet present on a blocklist.
No. Ranger works alongside existing security solutions and adds kernel-level tamper protection. It strengthens tamper resistance for products including CrowdStrike, Microsoft Defender, SentinelOne, Sophos, and Sysmon.
Ranger blocks the attempt to obtain kernel-level privileges before the attacker can disable endpoint defenses. Existing security tools remain active to alert, investigate, isolate, and respond to the original compromise.
See how Ranger prevents BYOVD attacks and strengthens the endpoint defenses you already use.
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