Austrian company AV-Comparatives analysed the performance of antivirus programs. The tests showed that Windows’ built-in antivirus solution depends heavily on cloud-based protection.
According to the report, Microsoft Defender has one of the lowest offline detection rates at 60.3%. This means it cannot adequately deal with virus threats without an internet connection.
Offline leader G Data
On the other hand, Microsoft Defender’s online performance is quite good. When connected to the Internet, it achieves an extremely high protection rate of 99.96%. In the report it ami shows that on top in the offline protection field is G Data with 98.6%.
[SOURCE]