bootkit Archives

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.

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.