Thursday, December 6, 2012

Hacking Pictures

So here's the story.  Ever heard of John McAfee?  Well if you've bought a computer in the last 10 years or so you should have.  He founded the popular antivirus software that bears his name.  Well if you didn't know he's been kinda hard to find lately.  He's been wanted for questioning by the Belize police regarding the murder of one of his neighbors.  Well McAfee took off and has for quite some time been taunting authorities regarding his whereabouts.  If you read the story I linked, you'll find that he has indeed been caught and it was totally his own fault.  McAfee talked to Vice Magazine and let them snap a picture with them.  Then Vice Magazine uploaded the image directly to their page.

If you didn't read the article, you're probably thinking the police saw it and learned his locale based on his surroundings.  And if you're thinking that I don't think you read the title of this blog entry carefully enough.  Turns out that the image was snapped on an iPhone.  Digital cameras and smartphones embed data into the images you take.  It's called EXIF data (that's exchangeable image format).  Among the data that gets embedded into the pictures are the date and time the image was taken, any software you might have used to produce it, the make and model of the device you used to capture the image, and, provided you have GPS, the exact location of where you took that picture.

Simple Nomad was in no mood to gloat about the detective work, saying by e-mail, “McAfee’s mistake was talking to the Vice guys, so ultimately his ego is the culprit.”
There's a simple reason why he didn't gloat.  While it was a brilliant idea to check the geolocation on the image, it's not entirely difficult to do.  In fact you can do it just as easily.  Here's how:

  1. Turn on the GPS on your cell phone and take a picture. Depending on your cell phone, you may have to enable the option that lets your camera know your location
  2. Download that picture into your computer.
  3. Download an image viewing program called Irfanview.  Make sure you install all the plugins too.
  4. Things only get slightly technical here.  Open the image you saved in Irfanview.  The look for  Image -> Information (see Image 1 below)
  5. In the window that pops up, look for the EXIF info button near the bottom. (Image 2 below)
  6. There you have it! Look for GPS Information.  You can plug those coordinates into Google Maps and easily find the exact location (well, not EXACT exact, but close enough) the image was taken.  There should even be a link to Google Earth and GeoHack if you're too lazy to plug in the numbers yourself (use GeoHack if you don't have Earth installed; it'll link you to Google Maps).

    Image 1
    Image 2

Fortunately for Simple Nomad and the authorities, GPS geotagging is set to default on iPhones.

Bet you're worried about Facebook now, aren't you.  You can relax (for now).  Facebook doesn't preserve the EXIF data when you upload images to the site.

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