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Microsoft Defender for Office 365 Blog
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Microsoft Defender for Office 365: Migration & Onboarding

RenWoods's avatar
RenWoods
Icon for Microsoft rankMicrosoft
Oct 22, 2025

Onboarding to Microsoft Defender for Office 365 is often treated as a quick setup task, but it should be seen as a critical opportunity to establish strong security foundations. In my roles supporting incident response and security operations in Microsoft 365, I have observed that onboarding is often underestimated. - Purav Desai, Dual Security MVP

This blog covers four key areas that are frequently missed, but they are essential for a secure and auditable deployment of Defender for Office 365. Before diving into the technical details, it is im...
Updated Oct 24, 2025
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PJR_CDF's avatar
PJR_CDF
Iron Contributor
Oct 23, 2025

I've worked with MDO for a long time and always wonder why the setting to prevent download of Malware infected files from SPO/OfB isnt set to on as the default? For 99.9% of use cases this is what's required so why have such an obvious gap as the default? 

In an ideal world this setting would be on by default and require additional authentication/approval steps to disable.

PaulNewell's avatar
PaulNewell
Icon for Microsoft rankMicrosoft
Oct 23, 2025

Thanks for the feedback, PJR_CDF​. This makes sense to me. This is something owned/controlled by the SharePoint Online & OneDrive for Business product group, so I will pass this along to them. 🙂