 the Dynamic Data Exchange protocol (DDE) in all supported editions of Microsoft Word.
2. Disable DDE Protocol in Microsoft Excel
Microsoft, however, hasn’t disabled DDE in Microsoft Excel. In the security advisory "Securely opening Microsoft Office documents that contain Dynamic Data Exchange (DDE) fields", Microsoft noted that Excel, in particular, depends on the DDE feature to launch documents. "Disabling this feature could prevent Excel spreadsheets from updating dynamically if disabled in the registry,” Microsoft said. “Data might not be completely up-to-date because it is no longer being updated automatically via live feed. To update the worksheet, the user must start the feed manually. In addition, the user will not receive prompts to remind them to manually update the worksheet.”
As early as 2007, Raymond Chen, who has been involved in the evolution of Windowsfor decades, said that "there is no technological reason for you to use DDE”. Chen, however, said that even if there’s no technological reason for you to use DDE, “you still have to be mindful of whether your actions will interfere with other people who choose to”.
3. Exercise Caution When Opening Suspicious File Attachments
As email attachments are a primary method by DDE attackers to spread malware, Microsoft recommends that users exercise caution when opening suspicious file attachments.
Steve E. Driz, I.S.P., ITCP