How to identify the malware in email protection?

Dear All,

I have set up the email protection in legacy mode.

And there were some mails blocked as malware that detected in Malware log viewer.

But I don't know why these mails was identified as malware detected, because there was no name showed in log viewer.

And email report can't identify the malware too...

How do I know why these mails was identified as malware emails?

Thanks~