We recently picked ransomware in one of the old emails, it was alerted through Defender. Is it possible to search all the different historical Malware or Ransomware or PUA files or emails that exist in our environment (Exchange Online, Sharepoint, etc...) and we've not been alerted or aware of them. The malware/PUA/Ransomware can be of any type or any name or any extension or any format and we are not aware of the details and would consider as concealed or archived in the user’s mailbox as an example.