bootkit Archives

Winsage

March 7, 2026

Microsoft’s Secure Boot certificates expire in June 2026, but older PCs may never get the fix

Every Secure Boot-enabled Windows PC relies on cryptographic certificates issued by Microsoft in 2011, embedded in the motherboard's firmware, to ensure a secure boot process. The first of these certificates will expire on June 24, 2026, which will affect the ability to receive future security updates for critical components of the Windows startup process. Microsoft is rolling out replacement certificates through Windows Update, marking a significant security maintenance effort. Secure Boot operates as a chain of trust with certificates stored in the motherboard's UEFI firmware, validating software before the operating system loads. The Platform Key (PK) is at the top of this chain, followed by the Key Exchange Key (KEK) and the Signature Database (DB). The replacement certificates introduced in 2023 restructure certificate management, separating responsibilities among different certificate authorities to enhance the trust model. Not all PCs are affected by the upcoming expiration; newer devices manufactured since 2024 already have the new certificates. Windows 10 users face challenges as support for this version ends in October 2025, and they will not receive the new certificates unless enrolled in Extended Security Updates. Home users should ensure their PCs are set to receive updates automatically, while enterprise environments require coordination for firmware updates before the Windows certificate update.

Winsage

March 6, 2026

Microsoft’s Secure Boot certificates expire in June 2026, but older PCs may never get the fix

Every Secure Boot-enabled Windows PC relies on cryptographic certificates issued by Microsoft in 2011 for boot process integrity. The first of these certificates will expire on June 24, 2026, impacting the ability to receive future security updates. Microsoft is rolling out replacement certificates through Windows Update, requiring collaboration between Microsoft, PC manufacturers, and users. Three critical certificates will expire: the Microsoft Corporation KEK CA 2011 and Microsoft UEFI CA 2011 in June 2026, and the Microsoft Windows Production PCA 2011 in October 2026. The new certificates introduced in 2023 have a restructured functionality to enhance security. Not all PCs are affected; newer devices manufactured since 2024 come with the new certificates. Windows 10 users face challenges as support ends in October 2025, and unsupported devices will not receive updates. Home users should ensure automatic Windows updates and check for firmware updates, while enterprise environments must verify firmware updates before applying certificate updates. The first certificate expiration is on June 27, 2026.

Winsage

February 12, 2026

Microsoft’s latest update patches six zero-days and two critical flaws – but is it another buggy mess?

Microsoft's February Patch Tuesday update addresses feature and security bugs, continuing the refresh of Secure Boot certificates to protect against bootkit malware. Secure Boot prevents malicious software from executing during startup by using trusted certificates, many of which are set to expire in June. The update is available for both Windows 11 and Windows 10 users, with the latter needing to be enrolled in the Extended Security Updates (ESU) program until October 2026. Windows 11 fixes include resolutions for full-screen gaming and WPA3-Personal Wi-Fi connectivity issues, while Windows 10 improvements address Chinese fonts, specific graphics processing units, and custom folder names in File Explorer. A bug causing unexpected restarts in Secure Launch-compatible PCs has also been fixed. The update includes 55 security patches, a decrease from January's 114, with two classified as critical and six identified as zero-day vulnerabilities. One vulnerability exploited in the wild could allow system privilege escalation, another could disrupt network connectivity, and a third could disable security controls and access sensitive data. Users can update their Windows 11 PCs through System > Windows Update, and Windows 10 users through System > Update & Security. Due to previous buggy updates, users may consider waiting a few days before installing the February update, with the option to uninstall if issues arise.

Winsage

January 20, 2026

Microsoft issues emergency patch for latest Windows bugs

Microsoft released the January Patch Tuesday update on January 13, 2026, addressing over 110 security vulnerabilities. The update introduced bugs affecting Windows 11, Windows 10, and Windows Server. The first issue involves authentication failures when connecting to a Cloud PC via Remote Desktop, primarily affecting Windows 11 25H2, Windows 10 22H2 ESU, and Windows Server 2025. The second issue affects systems with Secure Launch enabled, causing unexpected restarts instead of shutting down or entering hibernation mode, specifically impacting Windows 11 23H2. Microsoft has released emergency patches for the affected versions, which include: - Windows 11, versions 25H2 and 24H2 (KB5077744) - Windows 11, version 23H2 (KB5077797) - Windows 10, version 22H2 ESU and Windows 10 Enterprise LTSC 2021 (KB5077796) - Windows Server 2025 (KB5077793) - Windows Server 2022 (KB5077800) - Windows Server 2019 and Enterprise LTSC 2019 (KB5077795)

Winsage

June 11, 2025

A worrying Windows SecureBoot issue could let hackers install malware – here’s what we know, and whether you need to update

Researchers at Binarly have identified a critical vulnerability in a widely trusted BIOS update utility that operates on most modern systems using UEFI firmware. This utility, signed with Microsoft’s UEFI CA 2011 certificate, contains a flaw that could be exploited by malicious actors to disable essential security measures and install bootkit malware on personal computers. Microsoft addressed the issue by including a fix in its June 2025 Patch Tuesday cumulative update. The UEFI Secure Boot process is crucial for maintaining system integrity by verifying the authenticity of bootloaders and operating systems.