bootkit Archives

Winsage

June 25, 2026

Windows 11 Secure Boot update released to all, hours ahead of expiry

Microsoft has begun rolling out the Secure Boot 2023 certificate update to eligible Windows 11 and Windows 10 PCs ahead of the expiration of the Microsoft Corporation KEK CA 2011 on June 24, 2026. This update enhances device targeting data for automatic Secure Boot certificate updates. Secure Boot is a firmware-level security feature that verifies digital signatures of boot components to prevent rootkits and bootkits. The certificates for Secure Boot were first issued in 2011, with subsequent expirations for related certificates occurring in June and October 2026. Users can check their Secure Boot certificate status through the Windows Security app or System Information. If a PC does not receive the update, it will still boot normally but will lose the ability to receive future boot-level security updates. Multiple restarts after updates are expected due to the Secure Boot certificate process. A new folder, C:WindowsSecureBoot, is not malware but is used for staging cryptographic certificate files. Windows 10 users enrolled in the Extended Security Updates program will also receive the Secure Boot update, while those not enrolled will not. The expiration of the KEK CA 2011 means Microsoft will not be able to sign new Secure Boot revocation payloads using the old key, but existing signed payloads will remain functional.

Winsage

June 24, 2026

Windows 11 Secure Boot update released to all, hours ahead of expiry

Microsoft has begun rolling out the Secure Boot 2023 certificate update for eligible Windows 11 and Windows 10 PCs ahead of the expiration of the original certificates on June 24, 2026. The update includes additional device targeting data to increase coverage for automatic updates. Devices receive the new certificates after demonstrating successful update signals. The original Secure Boot certificates were issued in 2011, with expiration dates set for June 24, 2026, June 27, 2026, and October 19, 2026. Microsoft has been distributing replacement 2023 certificates since 2024, with the June 2026 update expanding eligible devices significantly. Users can check their Secure Boot status through the Windows Security app or System Information. If a PC did not receive the update, it will still function normally but may not receive future boot-level security updates. Multiple restarts after updates are expected behavior, and the SecureBoot folder in Windows is not malware. Windows 10 users in the Extended Security Updates program are also receiving the Secure Boot update. The expiration of the Microsoft Corporation KEK CA 2011 on June 24 means no new Secure Boot revocation payloads can be signed with the old key, but existing signed payloads will continue to function.

Winsage

June 21, 2026

Microsoft reveals how to verify Windows 11’s Secure Boot update, what to do if your PC missed it

The expiration of Microsoft's Secure Boot 2011 certificates on June 24 will not prevent older Windows PCs from booting, as confirmed by Microsoft. Devices will continue to operate normally, but they will miss future boot-level security updates, including updates to the Windows Boot Manager and mitigations for newly identified vulnerabilities. The ability to receive the Secure Boot 2023 update depends on the device firmware's compatibility, with many manufacturers, including Dell, HP, Lenovo, and ASUS, having cutoffs for BIOS updates based on the device's End of Service Life. Older PCs using Legacy BIOS or Compatibility Support Module (CSM) mode do not utilize UEFI Secure Boot, making the update irrelevant. Users running Windows 11 on unsupported hardware may have Secure Boot disabled or improperly configured. Without the 2023 certificates, devices cannot receive future revocation updates to the Secure Boot DBX, which lists compromised bootloaders. Users on Windows 10 with supported OEMs may receive the update if a compatible BIOS is available, while those on older PCs without updates can continue using their devices but will lack future security updates. The Secure Boot status can be checked through the Windows Security app, with color-coded badges indicating the status of the certificates.

Winsage

June 17, 2026

Windows and Linux users: The deadline to update Secure Boot keys is near

In 2012, a novel bootkit targeting Mac OS X systems emerged, infiltrating the EFI firmware. A basic bootkit for Windows 8 also appeared, compromising the UEFI bootkit. By 2013, a more sophisticated UEFI bootkit named Dreamboat was introduced for Windows. The first documented real-world UEFI attack occurred in 2018 with the malware LoJax, linked to a Kremlin-backed hacking group. In 2020, the second known UEFI malware, MosaicRegressor, was discovered, which verified the presence of a malicious file upon each reboot. New UEFI bootkits like ESpecter, FinSpy, and MoonBounce have since emerged. In response to the threat of UEFI bootkits, Microsoft collaborated with manufacturers to implement Secure Boot, a protocol that uses cryptographic signatures to ensure the integrity of firmware during startup.

Winsage

June 16, 2026

China-Linked SprySOCKS Backdoor Expands to Windows with Driver-Based Stealth

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

June 15, 2026

Microsoft released the Windows 11 Secure Boot update for all PCs, how to verify yours

Microsoft has expanded the rollout of the Secure Boot 2023 certificate update to more Windows 11 and Windows 10 devices with the June 2026 Patch Tuesday update (KB5094126). This update aims to ensure that most supported consumer PCs are classified as high confidence, meaning necessary certificates are either installed or will be applied automatically. Secure Boot is a firmware security feature that verifies the software attempting to load during the startup process, blocking unauthorized software. The certificates supporting Secure Boot, issued in 2011, are expiring in stages starting June 24, 2026, prompting Microsoft to deploy replacement certificates. Most home users do not need to take manual action as the updates will occur automatically via Windows Update. Users can check their Secure Boot certificate status in the Windows Security app. A yellow warning indicates pending compatibility data, while a red alert suggests a firmware incompatibility requiring a BIOS update. Multiple reboots during the update process are normal, and a new SecureBoot folder in Windows is for staging cryptographic files. Older PCs may experience longer update times, and some may not receive updates due to firmware issues. HP users should check for BIOS updates if encountering BitLocker recovery loops. IT administrators should monitor device classifications and manually initiate updates for devices not in the high confidence category. Devices with Secure Boot disabled cannot receive updates, leaving them vulnerable. The expiration of the Microsoft Corporation KEK CA 2011 certificate on June 24 does not immediately affect device functionality, but it limits Microsoft's ability to sign new bootkit blacklist updates.

Winsage

May 28, 2026

Your Windows PC has a security deadline in June 2026

A Secure Boot certificate refresh is being deployed across supported Windows devices via Windows Update. The Secure Boot certificates from 2011 will begin to expire in June 2026, prompting Microsoft to introduce new 2023-dated certificates to maintain security. Most users will require minimal action if their PCs are updated, but older devices may face challenges. The current certificates include: - Microsoft Corporation KEK CA 2011: expires June 24, 2026 - Microsoft UEFI CA 2011: expires June 27, 2026 - Microsoft Windows Production PCA 2011: expires October 19, 2026 The new certificates will remain valid until 2038, with plans for post-quantum cryptography around 2030. While PCs using the 2011 certificates will continue to function, they will lose access to new security protections, making them vulnerable to emerging threats. A notable example of such a threat is the BlackLotus bootkit, which exploited vulnerabilities to bypass Secure Boot. Microsoft's rollout strategy involves a staged update process that typically takes around 48 hours and may require restarts. Users are advised to keep Windows updated and check their Secure Boot status. Known issues may arise for older PCs, systems that bypassed Windows 11 requirements, Legacy BIOS systems, and custom firmware configurations. IT teams managing devices should inventory their systems, monitor specific event IDs, test updates, and document devices that cannot be updated.

Winsage

May 28, 2026

Windows Server 2016 Update: Disastrous Bug Breaks AD

Microsoft released a mandatory patch (KB5087537) for Windows Server 2016 to enhance cryptographic layers and address critical vulnerabilities. This update is essential for organizations using legacy workloads, as mainstream support ended in January 2022, but extended support continues until January 12, 2027. The patch aims to prepare systems for the expiration of Windows Secure Boot certificates in June 2026, which, if not updated, could compromise security and expose systems to malware. The update uses a phased deployment model and includes a new SecureBoot folder to assist IT professionals in managing certificate status. It also addresses various quality-of-life issues, including bugs affecting Remote Desktop Connection and authentication errors with Microsoft services. However, a significant issue arises when the host server name is exactly 15 characters long, causing failures in the domain controller discovery process and obstructing critical operations. This bug is linked to the historical 15-character limit of NetBIOS, which affects the Active Directory lookup mechanism. Microsoft has acknowledged the issue but has not provided a timeline for a fix, leaving administrators to either rename servers or uninstall the update. As the Secure Boot deadline approaches, IT departments must carefully assess their environments to avoid disruptions while ensuring security compliance.

Winsage

May 27, 2026

Your PC’s trust in Windows has an expiration date

Microsoft will change Secure Boot certificates in June 2026, impacting Windows 11 PCs. If users do not update the certificates, their PCs may still function but will lack critical boot updates and malware blacklists, potentially compromising security. Without the new certificates, systems cannot run the latest Windows Boot Manager, making them vulnerable to bootkit malware and hindering future Windows feature updates. Older computers using BIOS are exempt from this issue. The new Secure Boot certificates are valid until 2038. Users can check their Secure Boot status in the Windows Security app; a green circle indicates readiness for the deadline.

Winsage

April 16, 2026

Microsoft’s latest Windows update now confirms if your PC is Secure Boot-protected

Microsoft has introduced a new feature in Windows 11 and Windows 10 that informs users about the status of Secure Boot as part of the April Patch Tuesday update. This feature includes a visual indicator that shows whether devices have the latest Secure Boot certificates, which protect against bootkit malware. The Secure Boot icon can display in green, yellow, or red, indicating different security statuses: green means secure with no actions needed, yellow indicates a pending safety recommendation, and red signals that immediate attention is required. Users can check their Secure Boot status through Settings in both operating systems. It is important to install the latest Windows updates to ensure devices have the most recent Secure Boot certificates, as older certificates will expire in June. The April updates also address 164 vulnerabilities, including eight classified as critical and two identified as zero-day flaws. Users are advised to prioritize these updates to maintain system security.