Finding Hidden Metadata in Images (Oh, the Possibilities)

Did you know there is hidden data in your digital pictures? Well, there is, and that data might be a security risk to you. Think back at all of those pictures you're in and are connected with. I'm sure some of those you'd like to distance yourself from. And surely you wouldn't mind checking out the metadata in a few of those images. In this article, we'll be going over how to do just that.

What Is Metadata?

Metadata is nothing new, but with camera phones and other mobile devices becoming the standard for personal photography, new avenues open up for gaining knowledge on your target.

Metadata is simply data about data, or in our context, data about content. While the word has far reaching definitions, we will focus on how it applies to digital photos. Normally, this would contain information describing the type of image, when the image was created, and other details such as contrast, color and context. Basic stuff.

Sometimes you get more than that though. Sometimes you get names, dates, times of creation, and other identifying items. Some cameras even let you add your name in the setup, which goes into the metadata. And let's not forget about location. Geotagging is when actual location info is stored in the image. This is a growing trend, since more and more mobile phones are equipped with GPS. Using the techniques below, you'll be able to pull this GPS data and determine just where the picture was taken.

Let's take a look at a personal favorite program of mine, exiftool. 

Finding Metadata!

I am going to walk you through obtaining, installing and using exiftool. By the end of this article, you should be ready to perform your own investigation and data retrieval. You need:

• Exiftool
• Some digital pictures to look at
• A can-do attitude

Obtaining Exiftool

Use wget to make the downloading process simple. Wget is a great and powerful tool and usually beats downloads through your browser in speed and reliability. Just type:

$ wget http://owl.phy.queensu.ca/~phil/exiftool/Image-ExifTool-8.80.tar.gz

Extract and Run

Follow that up by expanding the tarball and moving into the directory with:

$ tar zxvf Image-ExifTool-8.80.tar.gz; cd Image-ExifTool-8.80/

Profit!

Let's take a look at the metadata of a picture my dear old mother sent to me this morning. For my own protection, this will not include any personal info, but it will show you the general output and commands to use.

$ ./exiftool [path and filename]

You can also use option flags to produce different output. Let's use the verbose flag of '-v':

$ ./exiftool -v [path and filename]

In Closing

Understanding metadata in images is critical. You might find yourself looking for someone else, or not wanting to be found at all. It's wise for the paranoid to check pictures that they're in for GPS tags and other possible identifying information, such as dates and software watermarks.

For those interested, Phil Harvey has written a well laid out breakdown of the more advanced applications for Exiftool. You can do more then just look at metadata, but not everyone needs to bother with it, so I left it out of the main article. But if you're curious, click above.

tl;dr

In case you just want the commands...

$ wget http://owl.phy.queensu.ca/~phil/exiftool/Image-ExifTool-8.80.tar.gz

$ tar zxvf Image-ExifTool-8.80.tar.gz; cd Image-ExifTool-8.80/

$ ./exiftool [path and filename]

Profit!!

Ever find anything interesting in your images? Ever pull metadata out of an photograph and locate someone? Share your stories with us! Questions? Comments? I would love to hear them. Shoot me a line below, send me a message or visit our forum!

Photos by Libby Arnold, ContractExpress