The observed threat involves the Akira ransomware affiliates exploiting vulnerabilities related to SonicWall VPN appliances to gain initial access into targeted networks. Following this initial compromise, the attackers employ a Bring Your Own Vulnerable Driver (BYOVD) technique by leveraging two common Windows drivers, rwdrv.sys and hlpdrv.sys. These drivers are legitimate but vulnerable, and their exploitation allows the attackers to evade or disable antivirus (AV) and endpoint detection and response (EDR) solutions. This evasion is critical for the attackers to maintain persistence and avoid detection during the pre-ransomware activity phase. The campaign is suspected to be driven by an unreported zero-day vulnerability in SonicWall VPNs, which are widely used for secure remote access. The use of BYOVD is a sophisticated tactic that involves loading vulnerable drivers to execute malicious code with kernel-level privileges, effectively bypassing security controls. The campaign has been linked to multiple recent Akira ransomware incident response cases, indicating an ongoing and active threat. Defenders are advised to harden SonicWall VPN configurations, apply any recommended mitigations, and utilize YARA detection rules provided by threat intelligence sources to identify and respond to this activity before ransomware deployment. The attack techniques correspond to MITRE ATT&CK tactics such as initial access (T1078), privilege escalation (T1068), persistence (T1547.006), defense evasion (T1562.001), and user execution (T1204.002). No public CVE or patch is currently available, and no known exploits in the wild have been confirmed, but the threat is active and evolving.

For European organizations, the impact of this threat is significant due to the widespread use of SonicWall VPNs in corporate and governmental environments for secure remote access. Successful exploitation can lead to unauthorized network access, enabling attackers to bypass AV/EDR protections and deploy ransomware payloads, resulting in data encryption, operational disruption, and potential data breaches. This can affect confidentiality, integrity, and availability of critical systems. The use of vulnerable drivers for AV/EDR evasion complicates detection and response efforts, increasing dwell time and the likelihood of successful ransomware deployment. Organizations in sectors with high reliance on SonicWall VPNs, such as finance, healthcare, manufacturing, and public administration, face elevated risks. Additionally, the presence of a zero-day vulnerability means traditional patching and signature-based defenses may be ineffective, requiring proactive threat hunting and monitoring. The ransomware nature of the Akira campaign also implies potential financial losses, reputational damage, and regulatory consequences under GDPR and other data protection laws if personal or sensitive data is compromised or unavailable.

European organizations should immediately review and harden SonicWall VPN configurations by disabling unnecessary services, enforcing strong authentication mechanisms (e.g., multi-factor authentication), and restricting VPN access to trusted IP ranges. Network segmentation should be implemented to limit lateral movement in case of compromise. Deploy advanced endpoint protection solutions capable of detecting BYOVD techniques and monitor for the presence or loading of the rwdrv.sys and hlpdrv.sys drivers, especially if they are unsigned or modified. Utilize the provided YARA rules from threat intelligence sources to detect malicious driver usage and pre-ransomware activity. Conduct regular threat hunting exercises focusing on kernel-level anomalies and unusual driver loads. Maintain comprehensive logging and monitoring of VPN access and endpoint behavior. Since no patch is currently available for the suspected zero-day, organizations should engage with SonicWall support for any interim mitigations or advisories. Incident response plans should be updated to include scenarios involving BYOVD and ransomware, ensuring rapid containment and recovery. User training to recognize phishing or social engineering attempts that may lead to initial access is also critical.