eclipse Archives

Winsage

April 19, 2026

Windows Defender Security Flaws Actively Exploited by Hackers

Three vulnerabilities in Microsoft Defender, known as BlueHammer (CVE-2026-33825), RedSun, and UnDefend, are being actively exploited by hackers. BlueHammer has been patched, while RedSun and UnDefend remain unpatched. The public release of exploit code has accelerated real-world attacks, affecting Windows 10, Windows 11, and Windows Server systems. Attackers have begun exploiting these vulnerabilities, leading to concerns about privilege escalation, disruption of security updates, and the rapid spread of attacks.

Winsage

April 18, 2026

RedSun: Windows 0day when Defender becomes the attacker

A vulnerability has been discovered in Windows Defender that allows standard users to exploit a logic error in the file remediation process, enabling code execution with elevated privileges without administrative access. This flaw, identified by security researcher Chaotic Eclipse, occurs because Windows Defender does not verify if the restoration location of flagged files has been altered through a junction point. The exploit, named RedSun, takes advantage of a missing validation in the MpSvc.dll file, allowing attackers to redirect file restoration to the C:WindowsSystem32 directory. RedSun operates by chaining together four legitimate Windows features: Opportunistic Locks (OPLOCKs), Cloud Files API, Volume Shadow Copy Service (VSS), and Junction Points. The execution of the exploit involves monitoring shadow copies, triggering Defender's detection, synchronizing OPLOCKs, and ultimately writing malicious binaries to the System32 directory. The root cause is the lack of reparse point validation in the restoration process, and currently, no patch or CVE has been assigned for this vulnerability. It affects Windows 10, Windows 11, and Windows Server 2019 and later, and organizations are advised to implement behavioral detection strategies until a fix is available.

Winsage

April 18, 2026

‘They mopped the floor with me and pulled every childish game they could’: Disgruntled researcher releases second major Windows zero-day — claims Microsoft ‘would ruin my life, and they did’

A new zero-day vulnerability in Microsoft Defender has been disclosed by a researcher known as "Chaotic Eclipse," who has created a proof-of-concept exploit called "RedSun." This vulnerability allows local privilege escalation to SYSTEM level on Windows 10, Windows 11, and Windows Server when Microsoft Defender is active. The vulnerability has attracted attention from antivirus vendors, with some detecting it on VirusTotal due to an embedded EIRCAR in the executable. Chaotic Eclipse previously disclosed another vulnerability named BlueHammer, which also allowed local attackers to gain SYSTEM or elevated permissions. The researcher expressed dissatisfaction with Microsoft's vulnerability disclosure process, recounting negative interactions with the company. A Microsoft spokesperson stated the company's commitment to investigating security issues and supporting coordinated vulnerability disclosure.

Winsage

April 18, 2026

‘They mopped the floor with me and pulled every childish game they could’: Disgruntled researcher releases second major Windows zero-day — claims Microsoft ‘would ruin my life, and they did’

A researcher known as “Chaotic Eclipse” has revealed a new zero-day vulnerability in Microsoft Defender, called “RedSun,” which allows local privilege escalation to SYSTEM privileges on Windows 10, Windows 11, and Windows Server when Microsoft Defender is enabled. The exploit has been confirmed to function correctly, and some antivirus vendors have begun detecting it. This follows another vulnerability disclosure by the same researcher, named BlueHammer, which also allows local attackers to elevate permissions. Chaotic Eclipse expressed dissatisfaction with Microsoft’s handling of vulnerability disclosures, claiming they were threatened and experienced frustration with the company’s response. A Microsoft spokesperson stated the company is committed to investigating reported security issues and supports coordinated vulnerability disclosure.

Winsage

April 17, 2026

Hackers are abusing unpatched Windows security flaws to hack into organizations

Hackers have exploited vulnerabilities in Windows systems, specifically targeting three flaws: BlueHammer, UnDefend, and RedSun. BlueHammer has been patched by Microsoft, while UnDefend and RedSun remain unaddressed. The exploitation is linked to code published by a researcher named Chaotic Eclipse, who criticized Microsoft for their response to vulnerabilities. All three flaws affect Windows Defender, allowing hackers potential high-level access to systems. Microsoft emphasized the importance of coordinated vulnerability disclosure to protect customers and the research community. The situation underscores the ongoing struggle between cybersecurity defenders and cybercriminals.

Tech Optimizer

April 16, 2026

Unpatched Microsoft Defender flaw lets hackers gain admin access

A security researcher named Chaotic Eclipse has discovered a significant vulnerability in Microsoft Defender that could allow hackers to gain administrative access to systems running Windows 10, Windows 11, and Windows Server. The vulnerability arises from Windows Defender's behavior of rewriting detected malicious files back to their original location instead of removing them, which can be exploited to overwrite system files and grant unauthorized users elevated privileges. This issue remains unaddressed by Microsoft, leaving millions of users vulnerable. Although there is no current evidence of active exploitation, the situation could change. Users are advised to consider additional antivirus solutions for enhanced security.

Winsage

April 16, 2026

A zero-day BlueHammer Windows exploit was leaked by a researcher fed up with Microsoft’s Security Response Center — and the rushed fix isn’t perfect

On April 2, 2026, a security researcher named Chaotic Eclipse announced a zero-day Windows exploit called BlueHammer, which allows attackers to gain SYSTEM privileges. Will Dormann, a principal vulnerability analyst, confirmed the exploit's functionality. Chaotic Eclipse criticized the Microsoft Security Response Center (MSRC) for its perceived incompetence, suggesting that prior attempts to resolve the issue privately were ignored. Dormann indicated that budget cuts at Microsoft may have led to a decline in the quality of the MSRC. BlueHammer was neutralized in the Windows 11 CVE-2026-33825 update released on April 14, 2026, but some components may still exist.

Winsage

April 10, 2026

Windows Zero-Day Published on Github as Microsoft Fails to Act

A security researcher named Chaotic Eclipse published a working exploit for a Windows zero-day vulnerability, called BlueHammer, on GitHub on April 2. The exploit allows attackers to gain SYSTEM-level privileges by exploiting a race condition in Windows Defender’s signature update mechanism. The exploit has gained significant attention, with over 100 forks and nearly 300 stars on GitHub. Will Dormann, a principal vulnerability analyst, confirmed that while BlueHammer is functional, it may not always operate reliably. Microsoft has not issued a patch for this vulnerability. The exploit targets the Windows Defender signature update process, allowing low-privilege attackers to manipulate a file path during operation, leading to access to the Security Account Manager (SAM) database. Currently, only 8 out of 72 cybersecurity vendors on VirusTotal flag the exploit file as malicious, which raises concerns about detection coverage. Microsoft reiterated its commitment to coordinated vulnerability disclosure but did not address the communication issues regarding the BlueHammer report.

Winsage

April 9, 2026

BlueHammer: Windows zero-day exploit leaked

A proof-of-concept (PoC) exploit called BlueHammer has been released on GitHub, targeting an unpatched local privilege escalation vulnerability in Windows. The exploit, attributed to users Chaotic Eclipse and Nightmare Eclipse, has been modified by security researchers to work on updated versions of Windows 10, 11, and Windows Server. The exploit manipulates Microsoft Defender to create a Volume Shadow Copy, allowing access to sensitive registry files and enabling the extraction of NTLM password hashes. This facilitates the alteration of a local Administrator's password and subsequent login. The exploit can duplicate the Administrator's security token and create a malicious Windows Service that runs with SYSTEM privileges. While there are no reports of BlueHammer being exploited by malicious actors, researchers warn that such PoC code can be weaponized quickly. Microsoft has committed to investigating reported security issues related to this vulnerability.

Winsage

April 7, 2026

Disgruntled researcher drops “BlueHammer” Windows zero-day LPE exploit

A security researcher, known as "Nightmare-Eclipse," released proof-of-concept exploit code for a Windows zero-day vulnerability called "BlueHammer," which allows local privilege escalation (LPE). The exploit has been validated by another researcher, Will Dormann, who confirmed it can escalate privileges on Windows systems, allowing non-administrative users to gain SYSTEM-level access. The exploit's reliability varies across different Windows versions, with inconsistent success rates reported. Microsoft has not acknowledged the vulnerability or provided a patch, raising concerns about potential exploitation by threat actors. Users are advised to restrict local user access, monitor for suspicious activity, and enable advanced endpoint protection.