Microsoft fixes bug behind ‘Defender Antivirus is turned off’ alerts

What happened

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

Why it matters

The development may change operating conditions or market expectations around Microsoft. Further confirmation and measurable outcomes matter.

Affected entities

View evidence

2 reports · 1 original report · 1 independent

1. BleepingComputerPrimary source · Supports · EN · 100%
   Microsoft fixes bug behind ‘Defender Antivirus is turned off’ alerts ↗Sep 18, 2026, 8:16 AM
2. BleepingComputerPrimary source · Supports · EN · 48%
   Microsoft Teams will let admins block custom file extensions ↗Sep 18, 2026, 9:58 AM

Claims

• Microsoft fixes bug behind ‘Defender Antivirus is turned off’ alerts Observed

Conflicts

No material conflict detected in the available evidence.

Timeline

1. September 18, 2026 at 8:16 AMFirst reported

Market move following event

Market reaction is not yet available for this asset and time window.

Score explanation