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.