Is Your Microsoft Word Document Leaking Secrets?

Chuck Lobert
March 31, 2014
Blog, Cybersecurity, Microsoft, Software

Just because you hit the delete button when using Microsoft Word doesn’t necessarily mean that your information is gone forever. Thanks to Word’s Track Changes feature, all of your deleted sentences can be easily retrieved. This is a very handy tool to help you out of a jam, but it can also be misused to leak secrets if you’re not careful.

To check if a document contains previously made edits like tracked changes, comments, hidden text, and other information, you will want to use the Document Inspector. To access this feature, go to File > Info > Check for Issues > Inspect Document. This will bring up the Document Inspector menu which will display six categories that you can inspect. They are:

Comments, Revisions, Versions, and Annotations
Document Properties and Personal Information
Custom XML Data
Headers, Footers, and Watermarks
Invisible Content
Hidden Text

Make sure that what you want inspected has the box corresponding to it checked, and then click Inspect.

You will now be given the inspection results, and if Document Inspector finds content in the categories that you selected it will give you the option to remove the content by selecting Remove All.

Why Would You want to Remove a Document’s Hidden Content?

If you plan on sharing your document, then you should use the Document Inspector to remove the hidden content before sharing it, especially if you’ve previously entered and deleted sensitive information. Without taking this security measure, you could share a document with a Word-savvy person that would be able to view what you deleted.

Here’s a worst-case scenario for you: Instead of making a sales proposal for a potential client from a new document, you take an old document and use it as a template by entering new data over old data. When finished, you send it to the potential client only to have them view the hidden data that you edited, and guess what, there happens to be some major discrepancies between the two sales proposals. You just lost a sale. Thanks Microsoft Word!

The Best Practice to Protect Yourself

The easiest way to prevent a shared document from leaking secrets is to use a clean template when making a new document. This will give you a master version to be used for editing and referencing that you wouldn’t share with your clients.