Qilin and Warlock Ransomware Deploy Vulnerable Drivers to Neutralize 300+ EDR Solutions
What Happened — Researchers at Cisco Talos and Trend Micro observed that ransomware groups Qilin and Warlock are leveraging the “bring‑your‑own‑vulnerable‑driver” (BYOVD) technique to load malicious drivers on compromised Windows hosts. The payload drops a forged msimg32.dll that disables more than 300 endpoint detection and response (EDR) products, clearing the way for ransomware encryption.
Why It Matters for TPRM —
- Attackers can silently bypass a wide range of security controls, increasing the likelihood of successful ransomware deployment.
- The BYOVD technique exploits publicly disclosed driver vulnerabilities, meaning any third‑party that supplies vulnerable drivers becomes an indirect attack surface.
- Organizations that rely on EDR solutions as a core control must reassess the effectiveness of those tools against low‑level driver attacks.
Who Is Affected — Enterprises across all sectors that deploy Windows‑based endpoints with EDR agents, especially those using legacy or unpatched drivers.
Recommended Actions —
- Inventory all third‑party drivers installed on endpoints and verify they are patched against known CVEs.
- Harden driver signing policies and enforce strict kernel‑mode code signing.
- Deploy complementary detection methods (e.g., behavior‑based monitoring, integrity verification) that can spot unauthorized driver loading.
- Review contracts with EDR vendors to ensure they provide timely updates for driver‑related mitigations.
Technical Notes — The ransomware uses a BYOVD approach, loading a malicious DLL masquerading as msimg32.dll to exploit a known driver vulnerability (CVE‑2025‑XXXX). Once loaded, the driver disables security‑related services and terminates EDR processes, effectively “silencing” the host. The technique bypasses traditional user‑space defenses and requires kernel‑level privileges. Source: The Hacker News