backdoor

Winsage
May 22, 2026
Microsoft's Digital Crimes Unit has filed a lawsuit against Fox Tempest, a criminal enterprise selling fraudulently signed malware to ransomware groups, affecting hospitals, schools, and critical infrastructure in ten countries. The lawsuit was filed on May 19 in the U.S. District Court for the Southern District of New York. Fox Tempest created a portal at signspace[.]cloud, offering a user-friendly interface for uploading malicious files and generating over 580 fraudulent Microsoft accounts to bypass identity verification. The group provided pre-configured virtual machines for customers to upload malicious payloads in exchange for signed binaries. Fox Tempest's operations were linked to a ransomware attack chain involving a counterfeit Microsoft Teams installer that deployed the Rhysida ransomware. This ransomware strain has caused significant breaches, including an October 2023 attack on the British Library, which resulted in a data exfiltration of about 600GB and recovery costs of £6 to £7 million, and a September 2024 attack on Seattle-Tacoma International Airport with a ransom demand of .8 million. Microsoft's civil litigation approach allowed for a quicker legal process, leading to the seizure of the signspace[.]cloud domain and the suspension of around 1,000 Fox Tempest accounts. Despite these actions, Fox Tempest has begun shifting to alternative code-signing services, highlighting the evolving nature of cybercrime and the need for users to verify software through independent channels. The confirmed targets of Fox Tempest included organizations in the United States, France, India, China, Brazil, Germany, Japan, the United Kingdom, Italy, and Spain.
Winsage
May 22, 2026
A security researcher known as Nightmare-Eclipse revealed a vulnerability in Windows 11, named YellowKey, which allows attackers to access BitLocker-encrypted drives through the Windows Recovery Environment. Microsoft acknowledged the vulnerability, assigned it the identifier CVE-2026-45585, and criticized the public sharing of its proof of concept. Currently, there is no patch available for the BitLocker bypass, but physical access to the device provides some protection. The vulnerability does not exist in Windows 10 due to differences in the Windows Recovery Environment. The attack requires a stolen Windows 11 laptop and a USB stick, and the vulnerable filesystems include NTFS, FAT32, and exFAT. Nightmare-Eclipse speculated that the bypass may function as a backdoor, while Microsoft referred to it as a "security feature bypass vulnerability."
Winsage
May 20, 2026
Microsoft has addressed the YellowKey vulnerability, a zero-day flaw in Windows BitLocker identified as CVE-2026-45585. This vulnerability allows unauthorized access to BitLocker-protected drives through a specific exploitation process involving 'FsTx' files. The flaw was disclosed by an anonymous researcher known as 'Nightmare Eclipse.' Microsoft has released mitigation strategies, including removing the autofstx.exe entry from the Session Manager's BootExecute REGMULTISZ value and reestablishing BitLocker trust for WinRE. Additionally, users are advised to change BitLocker settings from "TPM-only" to "TPM+PIN" mode, requiring a pre-boot PIN for drive decryption, and to enable "Require additional authentication at startup" for unencrypted devices.
Winsage
May 15, 2026
Microsoft confirmed a BitLocker-related issue caused by the April 2026 Security Update (KB5083769) for Windows 11, which led some devices to boot into the BitLocker recovery screen. A fix has been released, but it is currently available only for Windows 11, version 25H2, with Windows 10 and Windows Server users awaiting a solution. Administrators are advised to remove the "Configure TPM platform validation profile for native UEFI firmware configurations" Group Policy setting before installing the April 2026 update. Additionally, a security researcher named Chaotic Eclipse has developed a zero-day exploit called YellowKey, which can bypass BitLocker security using a USB stick, affecting Windows Server 2022 and 2025 but not Windows 10.
Winsage
May 14, 2026
An anonymous cybersecurity researcher disclosed two new zero-day vulnerabilities affecting Microsoft systems: YellowKey and GreenPlasma. YellowKey is a BitLocker bypass that operates as a backdoor within the Windows Recovery Environment, impacting Windows 11 and Windows Server 2022/2025. Exploiting YellowKey involves copying specially crafted files to a USB drive, connecting it to a Windows computer, and rebooting into WinRE. The researcher expressed skepticism about Microsoft's response time to this vulnerability, noting that using TPM+PIN does not mitigate the risk. GreenPlasma is a privilege escalation vulnerability that allows an unprivileged user to obtain a shell with SYSTEM permissions through arbitrary section creation in Windows CTFMON. The proof-of-concept for this exploit is incomplete but indicates potential manipulation of trusted privileged services or drivers. Additionally, a related attack against BitLocker was detailed by French cybersecurity firm Intrinsec, which exploits a boot manager downgrade using CVE-2025-48804 to bypass encryption protections on fully patched Windows 11 systems. This method allows attackers to boot from a controlled WIM while the boot manager checks the legitimate one, executing with the decrypted BitLocker volume. Despite Microsoft releasing fixes for this defect in July 2025, a flaw in Secure Boot verification allows a vulnerable boot manager to bypass BitLocker safeguards. To mitigate these risks, enabling a BitLocker PIN at startup and migrating to a new boot manager certificate is recommended.
Winsage
May 13, 2026
A cybersecurity researcher known as Chaotic Eclipse has released proof-of-concept exploits for two unpatched vulnerabilities in Microsoft Windows: YellowKey, a BitLocker bypass, and GreenPlasma, a privilege-escalation flaw. The YellowKey vulnerability affects Windows 11 and Windows Server 2022/2025, allowing unauthorized access to BitLocker-protected volumes by exploiting the Windows Recovery Environment. The exploit can be executed using specially crafted 'FsTx' files on a USB drive or directly on the EFI partition. Independent researcher Kevin Beaumont has validated the exploit, which can bypass BitLocker protections even in a Trusted Platform Module (TPM) environment. The GreenPlasma vulnerability allows unprivileged users to create arbitrary memory-section objects, potentially leading to privilege escalation. Chaotic Eclipse has expressed dissatisfaction with Microsoft's handling of bug reports, prompting the public disclosure of these vulnerabilities. Microsoft has stated its commitment to investigating security issues and updating affected devices.
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