Microsoft's newest software release for Linux is..

Will Windows Defender still be secure enough in 2026? We examine its strengths, real-world gaps, and what businesses need beyond basic antivirus.

While Windows Defender may appear fully operational to the casual observer, it can be covertly frozen on outdated threat signatures. The cybersecurity researcher Abdelhamid Naceri, operating under the pseudonym Nightmare Eclipse, recently released BigDiskBuster. This BigDiskBuster proof-of-concept tool is designed to stealthily sabotage Microsoft Defender updates while operating seamlessly in the background. Crucially, BigDiskBuster does not overtly disable the antivirus engine, nor does it abruptly terminate real-time protection protocols.

Over the weekend, security researcher Abdelhamid Naceri (also known as Nightmare Eclipse) released another Microsoft Defender zero-day exploit that blocks antivirus updates.

could use some rewriting, but you get the concept read more about New Windows Defender zero-day blocks Microsoft antivirus updates

Abdelhamid Naceri, also known as Nightmare Eclipse, has publicly revealed his identity and released BigDiskBuster, a new proof-of-concept exploit that interferes with Windows Defender platform and signature updates. He says the tool works on all supported Windows versions, though it remains buggy, and he also recounted a bitter dispute with Microsoft...

📰 Source : BleepingComputer — Date : 22 septembre 2026 Le chercheur en sécurité Abdelhamid Naceri (alias Nightmare Eclipse) a publié un nouveau proof-of-concept (PoC) zero-day nommé BigDiskBuster, ciblant Microsoft Defender.

Abres Seguridad de Windows, ves todo en verde y la pregunta llega sola: ¿con esto basta? Defender protege mejor de lo que mucha gente cree, y las pruebas independientes lo respaldan. Pero hay cosas que Seguridad de Windows no hace, y casi nunca es un fallo suyo: vienen apagadas, tu edición no las in

A new skeleton proof-of-concept demonstrates an arbitrary file read as SYSTEM on fully updated Windows systems, highlighting recurring flaws in Microsoft's patching process.

TL;DR A researcher published ShieldCrash, a Windows Defender 0day that bypasses Microsoft's patch for the ShieldBreak vulnerability (CVE-2026-6941). Both the vulnerability details and proof-of-concept exploit code are now public. The flaw reads arbitrary files as SYSTEM on all supported Windows versions. Why This Windows Defender 0day Matters The researcher, known as MSNightmare, released full details and working code on GitHub. Public exploit code lowers the bar for attackers.

At a glance Campaign Counterfeit software-download / fake installer campaign Threat actor Consistent with Silver Fox (Yinhu); moderate-confidence, not nation-state Targets China-based operations and Chinese-speaking users; many sectors Delivery vector Spoofed vendor download sites serving trojanized installers Key capabilities Persistence, SYSTEM privilege abuse, Defender tampering, C2 Source Microsoft Defender Experts TL;DR Attackers built high-fidelity clones of popular software sites. Victims download fake software installers that quietly deploy malware.

Paying no longer buys better basic malware protection

An active malware campaign is using bogus software-download websites to impersonate trusted vendors and distribute malicious installers. "The campaign has targeted users looking to download popular software and has resulted in compromises across multiple organizations and industries, primarily affecting China-based operations of multinational organizations and Chinese-speaking users," Microsoft

Die Updates für Windows und Defender verursachen Probleme mit der Maus und führen zu falschen Warnungen vor dem Defender-Status.