It's not a secret that Microsoft is responsible for protecting the Office 365 physical and virtual infrastructure and ensuring availability. Although Microsoft addresses certain security threats, it cannot prevent all malicious threats. But only users and businesses are responsible for protecting their data.
As I know with office 365 bacup and recovery solution you can reliably back up your Exchange Online data to on-site storage and rest assured your data is safe and accessible whenever you need it. You can choose what to restore and how to restore it. Recover mailbox folders or individual emails directly from backups, without starting a full-scale recovery.
