(Updated) Outlook: Share Word, Excel and PowerPoint local files via the new Outlook for Windows

🚨 The Signal: The new Outlook for Windows will now allow users to attach local Word, Excel, and PowerPoint files directly. This streamlines sharing but increases the risk of sensitive data leaving managed cloud environments if not properly governed.

The Impact

Users sending local files are affected, increasing the risk of unmanaged sensitive data being shared outside of controlled cloud environments.

• End Users: Risk of inadvertently sharing sensitive local files.
• Security Team: Increased challenge in monitoring and preventing data exfiltration.
• Compliance Team: Potential for non-compliance with data handling policies for local files.

The Action

1. Review and reinforce existing Exchange Online DLP policies to ensure coverage for local file attachments.
2. Communicate best practices to users regarding storing sensitive documents in OneDrive/SharePoint for better governance.
3. Audit existing Outlook/Exchange transport rules for any gaps in detecting sensitive information in attachments.

Domain: Exchange · Impact: medium · Workload: Exchange Online