Windows Defender on Windows 7 has not received signature updates for the last three weeks. For a yet unknown reason, Microsoft didn't update the signatures of the built-in anti-malware application the last 21 days.
Normally the anti-malware tool is updated through Windows Update, but users report they hadn't received signature updates since the 11th of June until yesterday. Both antivirus and malware expert Vesselin Vladimirov Bontchev and Windows expert Wood Leonhard report that Windows Defender on Windows 7 has received signature updates again.
Windows Defender is a free full-fledged antivirus tool on Windows 10 that in recent antivirus tests achieved maximum scores. On Windows 7 however, it's a basic anti-spyware tool that can run complimentary to third-party antivirus software.
It's unknown why Microsoft hasn't updated the signatures the last three weeks.
