[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"$fjc66IadYw0hduflSjNpSsMSWbwHocN-8Kgm45Me2xJU":3},{"article":4,"iocs":53,"watch_terms":58,"solutions":59,"lesson":150},{"id":5,"title":6,"slug":7,"summary":8,"ai_summary":9,"brief":10,"url":11,"image_url":12,"published_at":13,"ingested_at":14,"relevance_score":15,"entities":16,"category_id":30,"category":31,"article_tags":35},"3245b6d1-f459-4027-b4bf-97de5a0359eb","Nightmare Eclipse Drops Windows Zero-Day Exploit ‘SignDrop’","nightmare-eclipse-drops-windows-zero-day-exploit-signdrop-d89589","It abuses CLFS and Windows Defender to trigger arbitrary file creation in the context of the antimalware process. The post Nightmare Eclipse Drops Windows Zero-Day Exploit ‘SignDrop’ appeared first on SecurityWeek.","Security researcher Abdelhamid Naceri, known as Nightmare Eclipse, has released a zero-day exploit called SignDrop that targets Windows systems. The exploit allows a local user to gain System privileges by abusing a flaw in the Windows Common Log File System (CLFS) and Windows Defender. It has been tested on Windows 11 and Windows Server 2025, and is estimated to affect 80% of Windows installations older than 90 days. There is currently no evidence of this zero-day being exploited in the wild.","Nightmare Eclipse drops Windows zero-day exploit 'SignDrop' abusing CLFS and Windows Defender.","https:\u002F\u002Fwww.securityweek.com\u002Fnightmare-eclipse-drops-windows-zero-day-exploit-signdrop\u002F","https:\u002F\u002Fwww.securityweek.com\u002Fwp-content\u002Fuploads\u002F2026\u002F11\u002FNightmare-Eclipse.webp","2026-11-13T08:50:36+00:00","2026-11-13T09:00:05.650449+00:00",9,[17,20,23,25,28],{"name":18,"type":19},"Nightmare Eclipse","threat_actor",{"name":21,"type":22},"Windows 11","product",{"name":24,"type":22},"Windows Server 2025",{"name":26,"type":27},"CLFS","technology",{"name":29,"type":22},"Windows Defender","80544778-fabb-4dcd-aa35-17492e5dcf4f",{"id":30,"icon":32,"name":33,"slug":34},null,"Vulnerabilities","vulnerabilities",[36,41,46,48],{"category":37},{"id":38,"icon":32,"name":39,"slug":40},"574f766a-fb3f-487c-8d2c-0720ae75471b","Zero-day","zero-day",{"category":42},{"id":43,"icon":32,"name":44,"slug":45},"6cbdd207-aaa1-4176-9534-e156b125e917","Nation-state","nation-state",{"category":47},{"id":30,"icon":32,"name":33,"slug":34},{"category":49},{"id":50,"icon":32,"name":51,"slug":52},"e7b231c8-5f79-4465-8d38-1ef13aea5a14","Threat Intelligence","threat-intelligence",[54],{"type":55,"value":56,"context":57},"malware","SignDrop","Name of the zero-day exploit.",[21,24,29],{"controls":60,"vendors":146},[61,89,117],{"slug":62,"name":63,"problem":64,"products":65},"privileged-access-management","Privileged access management (PAM)","Admin accounts stop being one stolen password away from control of everything.",[66,74,81],{"vendor_slug":67,"vendor_name":68,"vendor_logo":69,"product_slug":70,"product_name":71,"url":72,"description":73},"palo-alto-networks","Palo Alto Networks","\u002Fvendor-logos\u002Fpalo-alto-networks.png","idira-privileged-access-management","Idira Privileged Access Management","https:\u002F\u002Fwww.paloaltonetworks.com\u002Fidira\u002Fhuman\u002Fprivileged-access-management","Privileged access management from the former CyberArk portfolio: vaulting, rotation, just-in-time access and session monitoring.",{"vendor_slug":75,"vendor_name":76,"vendor_logo":77,"product_slug":62,"product_name":78,"url":79,"description":80},"threatlocker","ThreatLocker","\u002Fvendor-logos\u002Fthreatlocker.png","Privileged Access Management","https:\u002F\u002Fwww.threatlocker.com\u002Fcapabilities\u002Fprivileged-access-management","Gives elevated rights to specific applications only where needed, so users do not need local admin accounts.",{"vendor_slug":82,"vendor_name":83,"vendor_logo":84,"product_slug":85,"product_name":86,"url":87,"description":88},"delinea","Delinea","\u002Fvendor-logos\u002Fdelinea.png","secret-server","Delinea Secret Server","https:\u002F\u002Fdelinea.com\u002Fproducts\u002Fsecret-server","Vault for privileged credentials with discovery, rotation and session recording.",{"slug":90,"name":91,"problem":92,"products":93},"patch-management","Automated patch management","Known holes get closed in days, not months.",[94,101,109],{"vendor_slug":95,"vendor_name":96,"vendor_logo":97,"product_slug":90,"product_name":98,"url":99,"description":100},"qualys","Qualys","\u002Fvendor-logos\u002Fqualys.png","Qualys Patch Management","https:\u002F\u002Fwww.qualys.com\u002Fapps\u002Fpatch-management\u002F","Patch deployment for operating systems and third-party applications, linked to vulnerability findings.",{"vendor_slug":102,"vendor_name":103,"vendor_logo":104,"product_slug":105,"product_name":106,"url":107,"description":108},"microsoft","Microsoft","\u002Fvendor-logos\u002Fmicrosoft.png","intune","Microsoft Intune","https:\u002F\u002Fwww.microsoft.com\u002Fen-us\u002Fsecurity\u002Fbusiness\u002Fmicrosoft-intune","Device management for Windows, macOS, iOS and Android, including update rings and compliance policies.",{"vendor_slug":110,"vendor_name":111,"vendor_logo":112,"product_slug":113,"product_name":114,"url":115,"description":116},"ninjaone","NinjaOne","\u002Fvendor-logos\u002Fninjaone.png","ninjaone-patch-management","NinjaOne Patch Management","https:\u002F\u002Fwww.ninjaone.com\u002Fpatch-management\u002F","Automated patching of operating systems and third-party applications from the cloud.",{"slug":118,"name":119,"problem":120,"products":121},"endpoint-detection-response","Endpoint detection and response (EDR and XDR)","Malware and hands-on-keyboard attackers on laptops and servers get spotted and stopped.",[122,130,138],{"vendor_slug":123,"vendor_name":124,"vendor_logo":125,"product_slug":126,"product_name":127,"url":128,"description":129},"sophos","Sophos","\u002Fvendor-logos\u002Fsophos.png","sophos-endpoint","Sophos Endpoint","https:\u002F\u002Fwww.sophos.com\u002Fen-us\u002Fproducts\u002Fendpoint-security","Endpoint protection with Intercept X anti-ransomware technology and EDR.",{"vendor_slug":131,"vendor_name":132,"vendor_logo":133,"product_slug":134,"product_name":135,"url":136,"description":137},"eset","ESET","\u002Fvendor-logos\u002Feset.png","eset-protect","ESET PROTECT","https:\u002F\u002Fwww.eset.com\u002Fint\u002Fbusiness\u002Fsolutions\u002Fendpoint-protection\u002F","Endpoint protection platform with detection and response add-ons.",{"vendor_slug":139,"vendor_name":140,"vendor_logo":141,"product_slug":142,"product_name":143,"url":144,"description":145},"withsecure","WithSecure","\u002Fvendor-logos\u002Fwithsecure.png","elements-xdr","WithSecure Elements XDR","https:\u002F\u002Fwww.withsecure.com\u002Fen\u002Ffor-business\u002Fplatform\u002Fxdr\u002F","Endpoint detection and response with extended detection, on the Elements cloud platform.",[147],{"slug":102,"name":103,"logo_path":104,"roles":148},[149],"affected",{"slug":151,"title":152,"body":153,"framework_refs":154,"framework_notes":160},"windows-zero-day-signdrop-highlights-privilege-escalation-risk-on-unpatched-systems","Windows Zero-Day SignDrop Highlights Privilege Escalation Risk on Unpatched Systems","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.",[155,156,157,158,159],"CIS Control 7: Continuous Vulnerability Management (v8)","CIS Control 4: Secure Configuration of Enterprise Assets and Software (v8)","NIST SP 800-53 SI-2: Flaw Remediation","MITRE ATT&CK T1068: Exploitation for Privilege Escalation","NIS2 Article 21(2)(e)",{"NIS2 Article 21(2)(e)":161,"NIST SP 800-53 SI-2: Flaw Remediation":162,"CIS Control 7: Continuous Vulnerability Management (v8)":163,"MITRE ATT&CK T1068: Exploitation for Privilege Escalation":164,"CIS Control 4: Secure Configuration of Enterprise Assets and Software (v8)":165},"This point covers vulnerability handling and disclosure practices, requiring entities to have processes that track and remediate vulnerabilities like the CLFS zero-day before public exploits are released.","SI-2 mandates identifying, reporting, and correcting system flaws within defined time frames, which would have required expedited patching of the CLFS vulnerability on affected Windows hosts.","CIS Control 7 requires organizations to continuously assess and remediate vulnerabilities; a mature program would have flagged the CLFS\u002FDefender flaw and prioritized patching before public exploit release.","SignDrop directly implements this technique by exploiting a software vulnerability to elevate a local user to SYSTEM privileges on Windows.","Restricting local user privileges through secure configuration baselines limits the attack surface a local privilege escalation exploit like SignDrop can abuse."]