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Fake Software Installers Disable Windows Update and Weaken Microsoft Defender

Fake software-download sites distribute installers that disable Windows Update and weaken Defender, attributed to China-linked cluster Silver Fox.

Microsoft says an active campaign uses counterfeit vendor websites on .com.cn and .hl.cn infrastructure with Chinese-language lures to deliver server-side generated installers that establish scheduled-task persistence, add Defender exclusions, delete shadow copies, and stop services including wuauserv, UsoSvc, uhssvc and WaaSMedicSvc. Victims span healthcare, manufacturing, gaming, technology, logistics, government and education, primarily China-based operations of multinationals and Chinese-speaking users. Microsoft assesses with moderate confidence the activity matches the Silver Fox (Yinhu) cluster, historically tied to Gh0st RAT and ValleyRAT, with C2 over non-standard ports like 5090 and 7088-7090 via domains iualef[.]net and oijfwe[.]net. Kaspersky separately detailed a QN Wallpaper DLL-sideloading chain delivering ValleyRAT.

The Hacker News · 13d agoMalware in the wild

Microsoft fixes record 964 flaws, including 2 exploited zero-days

Microsoft's September Patch Tuesday fixes a record 964 CVEs, including two actively exploited Windows privilege-escalation zero-days, CVE-2026-81963 and CVE-2026-85880.

Microsoft's September 2026 Patch Tuesday addresses 964 customer-patchable CVEs (104 Critical, 860 Important), the largest release on record, out of 974 total listed. Two actively exploited zero-days are fixed: CVE-2026-81963, a link-following elevation-of-privilege flaw in the Windows Update Stack, and CVE-2026-85880, a Windows ALPC heap overflow enabling AppContainer sandbox escape, both with CVSS 7.8. Both zero-days were exploited before a patch was available and grant SYSTEM-level access after an initial foothold. The release also includes high-severity RCE fixes for Windows DNS Server, Remote Desktop Services, Exchange Server, SharePoint, and SQL Server.

Malwarebytes Labs · 6d agoExploit / PoC in the wildCVE-2026-81963CVE-2026-858801

Microsoft’s September 2026 Patch Tuesday addresses 964 CVEs (CVE-2026-81963, CVE-2026-85880)

Microsoft's September 2026 Patch Tuesday fixes a record 964 CVEs, including two zero-days actively exploited in the wild.

Microsoft patched a record 964 CVEs in its September 2026 Patch Tuesday release, with 101 rated critical and 824 rated important, making it the largest Patch Tuesday to date. The release includes fixes for two zero-days that were exploited in the wild, with CVE-2026-81963 and CVE-2026-85880 highlighted in the release. Affected products span Windows core components, Office, Exchange, .NET, Visual Studio, Active Directory services (including AD CS and AD FS) and numerous Azure services. Tenable notes the release surpasses July's as the biggest ever.

Tenable Blog · 7d agoVulnerability in the wildCVE-2026-81963CVE-2026-858801

September 2026 Patch Tuesday: Record patch count, 2 zero-days, and a SigRed successor

Microsoft's September 2026 Patch Tuesday delivers a record patch count, fixing two exploited zero-days and a wormable DNS flaw dubbed a SigRed successor.

Microsoft's September 2026 Patch Tuesday sets another record patch count, fixing two vulnerabilities exploited as zero-days: CVE-2026-81963, a Windows Update Stack low-privilege-to-SYSTEM escalation reported by MSTIC, and CVE-2026-85880, a Windows Advanced Local Procedure Call escalation reported by Proofpoint. Zero Day Initiative's Dustin Childs urges priority on a cluster of 20 potentially wormable bugs including DNS RCE CVE-2026-69730, described as a spiritual successor to SigRed, plus Kerberos authentication bypass CVE-2026-69676 that could give any authenticated domain user RCE on domain controllers, and Exchange RCE CVE-2026-55007 via a malicious Visio attachment. All Windows fixes are bundled in cumulative updates, and experts stress prioritizing exploitable, reachable flaws over raw patch counts.

Help Net Security · 6d agoAdvisory in the wildCVE-2026-81963CVE-2026-85880CVE-2026-69730+4 CVEs

September 2026 Microsoft Patch Tuesday, (Tue, Sep 8th)

Microsoft's September 2026 Patch Tuesday fixes a record 973 vulnerabilities, including 113 critical and two Windows privilege-escalation flaws already exploited in the wild.

Microsoft patched 973 vulnerabilities this month, its largest Patch Tuesday ever and far above the previous record of 664 set in July 2026, with 113 rated critical. Two Important elevation-of-privilege flaws (CVSS 7.8) are confirmed exploited in the wild: CVE-2026-81963 in the Windows Update Stack (improper link resolution, affects Windows 11 and Server 2025) and CVE-2026-85880 in Windows ALPC (heap-based buffer overflow allowing sandbox escape to SYSTEM, affects Windows 10 and Server 2012-2022). Critical unauthenticated RCEs (CVSS 9.8) were also fixed in Skype for Business Server (CVE-2026-66302), Windows Message Queuing (CVE-2026-69579), and Windows RRAS (CVE-2026-69590). SANS urges prioritizing the two exploited EoP fixes, then patching exposed MSMQ, RRAS, and Skype for Business deployments.