Nightmare Eclipse Drops Windows Zero-Day Exploit ‘SignDrop’

Security researcher Abdelhamid Naceri publicly released a working zero-day exploit called SignDrop that abuses flaws in the Windows Common Log File System (CLFS) and Windows Defender to elevate a local user's privileges to SYSTEM level. With an estimated 80% of Windows installations older than 90 days potentially affected, the breadth of exposure underscores how quickly unpatched environments become high-value targets. The public release of a functional exploit dramatically shortens the window between vulnerability disclosure and active exploitation in the wild. Organizations that lack disciplined patch cycles or automated vulnerability tracking are especially at risk of rapid compromise once threat actors adopt this tool. This incident reinforces that privilege escalation vulnerabilities on widely deployed operating systems demand urgent remediation priority.