您好，
引用：Windows Defender is installed with the operating system on Windows 10 PC's.
Troubleshooting Windows Defender or Endpoint Protection client
https://docs.microsoft.com/en-us/sccm/protect/deploy-use/troubleshoot-endpoint-client
Windows 10 上面默认安装的SCEP 叫 Windows Defender 实际上是一个产品。
更多信息，可以参考下面这个链接：
Definition updates for Windows Defender Antivirus and other Microsoft antimalware
https://www.microsoft.com/en-us/wdsi/definitions
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