You can create a link in PowerPoint that launches a file that you have added to the Attachments section. Here's how:
Add an attachment to your presentation.
Right-click an object or text in PowerPoint and select Hyperlink.
In the address section, type the following: data/downloads/yourfilename.pdf
For more information on creating a button that hyperlinks to a file in the Attachments section, please see the screencast below:
Test the content in the environment you publish for to make sure it works. For more details, see Hyperlink in PowerPoint doesn't work.