Qilin and Warlock Ransomware Use Vulnerable Drivers to Disable 300+ EDR Tools

The modern cyber threat landscape is evolving at a pace that outstrips traditional defense mechanisms, and the latest security reports from Cisco Talos and Trend Micro shed light on an exceptionally effective method used by ransomware groups. Operators associated with Qilin and Warlock operations have begun mass-exploiting a technique known as BYOVD (Bring Your Own Vulnerable Driver). The goal is to completely blind protection systems by disabling over 300 EDR (Endpoint Detection and Response) tools, opening the way for hackers to engage in unhindered data exfiltration and asset encryption.

The scale of the problem is massive because this technique strikes at the foundation of trust in operating systems. By utilizing legitimate but vulnerable drivers, attackers gain kernel-level privileges, allowing them to manipulate processes that theoretically should not be touched by any external program. According to the Zscaler ThreatLabz 2026 VPN Risk Report, the progressive integration of artificial intelligence into offensive tools has drastically shortened human reaction time, making remote access the fastest path to breaching corporate infrastructure.

Anatomy of the Qilin attack and the msimg32.dll library

Analysis conducted by experts from Cisco Talos showed that Qilin group attacks are characterized by precise preparation of the environment for future infection. A key element of the arsenal is a malicious DLL library named msimg32.dll. Once injected into the system, the malware initiates a procedure to identify installed security solutions. This is not a random action – the target list includes hundreds of products from leading defense technology providers.

Once a protection system is identified, the Qilin and Warlock groups load a legitimate, digitally signed driver onto the infected machine that contains a known security vulnerability. Because the driver is trusted by the operating system, Windows control mechanisms allow it to run. Attackers then exploit the aforementioned vulnerability to execute code with the highest privileges, allowing them to forcibly terminate antivirus processes and monitoring tools before they can send an alert to administrators.

• Number of neutralized tools: Over 300 unique EDR and antivirus solutions.
• Key component: Malicious msimg32.dll library.
• Technique: BYOVD (Bring Your Own Vulnerable Driver) exploiting vulnerabilities in legitimate software.
• Result: Complete vulnerability of the host to data encryption.

Warlock and the automation of defense system paralysis

The Warlock group, often operating in a similar paradigm to Qilin, focuses on automating the security elimination process. Utilizing the BYOVD technique allows them to bypass protections that were previously considered effective against ransomware. Traditional solutions based on signatures or behavioral analysis often fail when the monitoring tool itself is "killed" at the kernel level. This is a battle at a level where security software has the fewest touchpoints with the user and the most with low-level CPU and memory architecture.

In the Cybersecurity Insiders report cited by Zscaler, it was emphasized that vulnerabilities in remote access and VPNs are currently the most popular entry point for groups like Warlock. Once an attacker is inside the network, their priority is not immediate encryption, but "silencing" the environment. Thanks to the BYOVD technique, this process has become almost invisible to standard Security Operations Centers (SOC). Disabling 300 different tools suggests that these groups possess an extensive database of exploits for drivers originating from hardware manufacturers, gaming components, or diagnostic tools.

The application of AI by cybercriminals further complicates the situation. Automatic scanning of systems for specific driver versions that can be used for a BYOVD attack drastically accelerates the reconnaissance phase. According to Zscaler ThreatLabz, the time window in which a human can react to a breach has practically ceased to exist. The attack occurs at machine speed, and disabling EDR is only one of the first steps in a long attack chain.

The crisis of trust in signed drivers

The problem facing IT departments is structural in nature. Operating system architecture relies on trust in digital signatures. If a driver is signed by a recognized manufacturer, the system assumes it is safe. The Qilin and Warlock groups ruthlessly exploit this fact. They do not need to create their own suspicious drivers – it is enough to find an old version of legitimate software (e.g., a driver for an old network card or a CPU overclocking tool) that has a documented buffer overflow bug or the ability for arbitrary memory writes.

"AI has drastically shortened the human reaction window, turning remote access into the fastest path to data security breaches in 2026." — Zscaler ThreatLabz 2026 VPN Risk Report

This approach means that the fight against Qilin is no longer just about blocking malicious IP addresses or removing known viruses. It requires a rigorous driver management policy and blocking those found on vulnerability blacklists. Unfortunately, on a global scale, many organizations do not have the appropriate tools to verify every loaded driver for historical security vulnerabilities, making the BYOVD technique one of the most destructive methods in the arsenal of modern ransomware.

The evolution of the Qilin and Warlock groups toward such advanced defense neutralization methods indicates the professionalization of cybercrime. The focus on disabling 300+ EDR tools proves that attackers are no longer afraid of confrontation with top security solutions – they simply remove them from the equation before proceeding with the actual attack. In a world where AI assists the network penetration process, the only effective defense becomes a Zero Trust model at the kernel level, which prevents the loading of any vulnerable drivers, regardless of their certification.