Microsoft fixes known issue causing Windows Defender crashes

Microsoft has resolved a bug that caused Windows Defender to crash after a recent security update, resulting in 0xc0000005 access violation errors on some affected systems.

Microsoft Defender is a security software designed to provide real-time protection against malware, viruses, ransomware, and spyware on Windows, macOS, Linux, Android, and iOS devices.

According to reports on social media and Microsoft's support site, users began seeing "Threat service has stopped. Restart it now" error messages on Windows 10 and Windows 11 devices starting Tuesday afternoon, prompting some affected customers to reinstall the operating system.

"Beginning this morning, quick or full scans are failing, and will occasionally fail to the point where the Defender service needs to be restarted," one Windows system admin said.