It’s official: Presentations built with Microsoft PowerPoint are unsafe because of built-in supports for Microsoft’s own Object Linking and Embedding (OLE) protocol. Actually any Office document is potentially unsafe since they can all access the same protocol.
Any Office document that suddenly displays a User Account Control (UAC) prompt is infected and is trying to tunnel into your Windows installation. Diabolical!
The full technical stuff can be read here. But there’s a quick fix:
Download and install the OLE packager Shim Workaround to fix the PowerPoint issue, but remember this is not full patch; that’s in development for later release.
Try and avoid PowerPoint. Most presentation can be made in person without numerous slides that only put viewers to sleep 🙂