Hidden picture info in your Office documents
The BBC has a ‘long read’ about hidden information inside almost all photos. Office Watch has talked about this problem many times before including how the extra image data hides in Microsoft Office documents, despite the ‘Document Inspector’.
It’s too easy just to think of an image as just what you see on the screen but there are more details available. Ignore all the talk about EXIF and metadata for a moment, the ‘hidden’ picture information is like the handwritten notes on the back of a paper photo, a bit like this:
Think of that level of detail hidden on every digital photo you take and it’s copied when you send the picture.
Image EXIF or metadata isn’t hard to find. In Windows, right-click on an image in Explorer, choose Properties | Details. Scroll down to see all the extra info saved, like the type of camera, camera settings, date photo was taken and usually the location of the photo.
MacOS, right-click on an image then ‘Get Info’ to see all the extra photo details.
The image detail is really useful information. It allows modern photo programs to group by date taken and even map photos by their location.
But that same information can be extracted and used against you. Revealing, for example, your home location or children’s school details.
When you Insert | Picture into a Word, Excel or PowerPoint document or Outlook email, the entire image file is added to the document. That includes all the ‘hidden’ image details.
See the BBC article The hidden fingerprint inside your photos
Microsoft’s solution to privacy concerns is the Document Inspector, but as Office Watch pointed out 5 years ago, image meta-data is not checked for. There’s not even a general warning about the risk.
Image privacy breach in Microsoft Office has more details and tips on how to remove the extra data from pictures already in Office documents.
Printer Dots
The same BBC article mentions the secret printer dots used to track when, where and likely who printed a document.
Secrets left in docs after Document Inspector in Office
More secrets left in Office documents
Saving Word document with automatic Document Inspector
Why you must use the Document Inspector
Does a document name reveal your secrets?