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

Think Windows 11's antivirus is broken? Thankfully it isn't, although the app is suffering from a pretty frustrating bug.

On some PCs, Windows 11 has been incorrectly warning that Microsoft Defender is turned off, even when it isn't, for almost ...

A researcher who calls himself Nightmare Eclipse published a free tool on September 19, 2026, that can quietly stop Windows ...

Per Windows Latest, “in our tests, we found that the Windows Security app, which manages Microsoft Defender Antivirus, randomly throws up ‘Turn on virus protection’ pop-ups when you boot Windows and ...

Microsoft has resolved a known issue that causes incorrect alerts warning that Defender Antivirus was turned off after installing recent updates.

Microsoft has fixed the bug that made Windows Security wrongly claim Microsoft Defender Antivirus was turned off. According ...

BigDiskBuster can block Microsoft Defender updates by filling disk space, leaving detection content stale; no patch or advisory exists.

The false notification stating that "Antivirus is disabled," despite Microsoft Defender working normally, was reported to ...

Serial Microsoft zero-day leaker NightmareEclipse has found another way to mess with Windows Defender, this time by stopping ...

After installing the latest Defender Antivirus update for Windows 11, users have started reporting that their operating ...

Microsoft has a new Defender anti-virus update for Windows 11 and 10 images. The new update patches several flaws. Following the one for Lumma last month, Microsoft has also published a new Defender ...