cybersecurity researchers have identified a new ransomware family, named Reynolds, that incorporates a sophisticated technique to disable endpoint security tools on infected computers. The malware embeds a vulnerable but legitimate driver within its own payload, allowing it to bypass critical defenses. This development represents a significant escalation in ransomware tactics, directly targeting the security software designed to stop such attacks.
Technical Mechanism of the Attack
The Reynolds ransomware utilizes a method known as Bring Your Own Vulnerable Driver, or BYOVD. This approach involves bundling a signed driver from a legitimate hardware or software vendor that contains a known security flaw. Once executed on a target system, the ransomware exploits this driver flaw to gain high-level system privileges.
With these elevated privileges, the malware can then tamper with or completely shut down Endpoint Detection and Response, or EDR, software. EDR tools are a primary line of defense for organizations, continuously monitoring endpoints for malicious activity. Disabling them leaves systems exposed and allows the ransomware to encrypt files without obstruction.
Implications for Enterprise Security
The integration of BYOVD directly into the ransomware payload marks a concerning trend. Previously, such driver-based attacks often required separate, preparatory steps. By embedding the tool within itself, Reynolds streamlines the attack process and increases its chances of success against protected networks.
Security analysts note that this technique is particularly dangerous because it abuses trusted, signed code. This can allow the malicious actions to evade initial detection mechanisms that whitelist software from reputable sources. The attack highlights a weakness in the trust model of digitally signed drivers.
Industry and Expert Response
In response to the growing BYOVD threat, major security vendors and operating system developers have implemented new safeguards. Microsoft, for instance, has introduced features like Hypervisor-Protected Code Integrity, which helps prevent unauthorized drivers from loading in Windows environments.
Cybersecurity firms are advising organizations to adopt a layered defense strategy. Recommendations include implementing driver allow-listing policies, regularly updating all software to patch known driver vulnerabilities, and using security solutions that can detect and block malicious driver activity at the kernel level.
Looking Ahead
Security researchers expect ransomware groups to continue refining and adopting the BYOVD technique. The disclosure of the Reynolds ransomware will likely prompt further analysis from the global cybersecurity community, leading to updated detection signatures and defensive recommendations. Organizations are urged to review their endpoint security configurations and ensure they have mitigations in place for this class of attack, as similar methods are anticipated in future ransomware campaigns.
Source: Cybersecurity Research Reports
