kernel drivers

Winsage
June 17, 2026
The Windows variant of SprySOCKS malware, developed by the Chinese threat group Earth Lusca, targets government entities globally and features advanced capabilities such as rootkit-level stealth and extensive command-and-control (C2) functionalities. It operates on Windows systems, utilizing two main variants: WINDRV, which includes kernel drivers for stealth operations, and WINPLUS, a streamlined backdoor. The malware can communicate over TCP, UDP, and WebSocket, offering over 30 C2 commands for various operations, including system information gathering and keystroke logging. WINDRV loads a driver named ‘RawWNPF’ into memory using another signed kernel driver, allowing it to conceal processes and achieve persistence. The malware's design incorporates open-source elements and exploits vulnerabilities in the software supply chain, notably using a leaked certificate for driver signing. To combat SprySOCKS, organizations are advised to implement advanced endpoint detection and response (EDR) solutions, maintain regular patching, and manage supply chain risks vigilantly. The malware's adaptability and reliance on legitimate certificates complicate detection efforts, necessitating continuous refinement of security practices.
Winsage
June 16, 2026
Cybersecurity researchers have identified two new Windows variants of the SprySOCKS backdoor, named WINDRV and WINPLUS, which were previously thought to be exclusive to Linux systems. Both variants feature hard-coded command-and-control configurations and can communicate via TCP, UDP, and WebSocket protocols. They support over 30 commands for operations such as system information collection and file management. WINDRV employs kernel drivers for stealth, obscuring network connections and allowing TCP traffic diversion. SprySOCKS was first documented by Trend Micro in September 2023, linked to the Chinese state-sponsored threat actor Earth Lusca, also known as FishMonger. The Windows variants belong to version 1.8 of SprySOCKS and utilize a kernel driver named RawWNPF for enhanced stealth. The attack chain begins with an initial access method that drops a batch script, leading to the installation of the backdoor. Evidence suggests these variants may have been used in attacks against government organizations in Honduras, Taiwan, Thailand, and Pakistan between 2023 and 2024. The WINPLUS variant was first detected in July 2024 in Pakistan. There are indications of a potential UEFI bootkit involvement exploiting CVE-2023-24932, a vulnerability in the Windows Boot Manager.
Winsage
May 11, 2026
Open-source endpoint detection tools have typically been divided between Windows and Linux, with Windows solutions focused on Sysmon and Linux solutions on eBPF or auditd. Rustinel is a Rust-based endpoint agent that consolidates these efforts by gathering telemetry from both operating systems using ETW on Windows and eBPF on Linux, normalizing the data into a unified model. It evaluates the information against Sigma rules, YARA signatures, and atomic indicators of compromise, storing alerts in ECS-compatible NDJSON format for integration with SIEM or log-analysis platforms. Rustinel supports a range of events on Windows, including process creation, network activity, and PowerShell executions, while Linux support currently includes process, network, file, and DNS telemetry. It operates in user mode on both platforms, requiring specific conditions for installation. Unlike commercial EDR solutions that use kernel drivers, Rustinel's user-mode design prioritizes simplicity and stability, although it acknowledges limitations in tamper resistance and visibility. The agent utilizes three detection engines: Sigma for behavioral matching, YARA for scanning executables, and an IOC engine for deterministic checks. While it leverages existing content familiar to defenders, it has coverage gaps for certain advanced threats. Rustinel is available on GitHub under the Apache 2.0 license.
Winsage
May 10, 2026
Microsoft's April 2026 Windows security update, KB5083769, may disrupt image-mount operations for backup applications such as Macrium Reflect, Acronis Cyber Protect Cloud, UrBackup Server, and NinjaOne Backup due to the addition of the psmounterex.sys kernel driver to its Vulnerable Driver Blocklist. This action was taken to address a high-severity buffer overflow vulnerability, CVE-2023-43896. The inclusion of this driver in the blocklist has rendered several backup products inoperable, and Microsoft will not retract the block for security reasons. Administrators can use Event ID 3077 in the Code Integrity log to confirm that the blocklist is causing the failures. Microsoft advises updating backup applications to versions that include necessary driver protections instead of uninstalling or pausing the security patch. Additionally, the April updates have caused other issues, such as failures in Windows Server installations and devices booting into BitLocker recovery mode.
Winsage
May 7, 2026
The Windows 11 security update KB5083769, released on April 14, 2026, introduces changes to the psmounterex.sys driver, causing compatibility issues with third-party backup solutions such as Macrium Reflect, Acronis Cyber Protect Cloud, UrBackup Server, and NinjaOne Backup. Microsoft states this is a necessary security adjustment, not a bug. The update also adds known vulnerable kernel drivers to a blocklist to enhance system security. Users can check if a driver is blocked by using the Event Viewer and looking for Event ID 3077 associated with a specific Policy ID.
Winsage
April 7, 2026
On March 26, 2026, Microsoft announced that starting with the April security update, it will eliminate trust in kernel drivers from the previous Cross-Signed Program for Windows 11 versions 24H2, 25H2, 26H1, and Windows Server 2025. Only drivers that have passed the Windows Hardware Compatibility Program (WHCP) or are on Microsoft's allow list will be allowed to load by default. This change aims to enhance security by establishing a robust chain of trust and addressing vulnerabilities associated with old kernel drivers. Users of older hardware that rely on specialized drivers may face challenges, as drivers not WHCP-signed or explicitly allowed will be excluded from the trusted zone.
Winsage
March 31, 2026
Microsoft will eliminate default trust for kernel drivers signed through the outdated cross-signed root program with the April 2026 Windows update. All new kernel drivers must be certified via the Windows Hardware Compatibility Program (WHCP). This change will affect Windows 11 builds 24H2, 25H2, and 26H1, as well as Windows Server 2025, with future versions following the same standards. The update will begin in evaluation mode, monitoring driver loads for compliance before transitioning to enforcement mode. An allow list of reputable drivers will be maintained for legacy hardware, and enterprises can use Application Control for Business policies to authorize specific drivers. Users with older hardware may face compatibility issues if their drivers are not WHCP-certified.
Winsage
March 27, 2026
Microsoft is enhancing the security of the Windows kernel by eliminating trust for kernel drivers not certified through the Windows Hardware Compatibility Program (WHCP) starting with the April 2026 Windows Update. This change specifically targets kernel drivers signed by the now-obsolete cross-signed root program, which has been associated with security vulnerabilities. The new policy will initially be introduced in an "evaluation mode" to monitor and audit driver loads for potential compatibility issues. Custom kernel drivers can still be used under the Application Control for Business policy, but must be signed by an authority within the device's Secure Boot Platform Key or Key Exchange Key variables. The changes will impact Windows 11 versions 24H2, 25H2, 26H1, and Windows Server 2025.
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