Hackers Unveil al-Qaida Video Tricks

In a presentation at the Black Hat conference here Tuesday, Neal Krawetz of Hacker Factor showed how basic manipulations to images can be revealed through digital analysis.

After presenting on the specific techniques he used, Krawetz launched into what he called the case of "Dr. Z," who happens to be Ayman al-Zawahiri, the No. 2 man in al-Qaida.

Using a photo that originally appeared on December 20, 2006, in USA Today, al-Zawahiri appears to be seated before a large banner with a desk underneath. On the desk, in the photo, is a tiny cannon. Yet in the text, al-Zawahiri is described as sitting with "a rifle behind his shoulder that was leaning against a plain brown backdrop."
Using the techniques demonstrated earlier in the talk, Krawetz deconstructed the image to show a halo around al-Zawahiri that suggests that he was likely sitting in front of a monochromatic screen. Even the letters on the banner had been altered. Further, the overall image had been cropped from the original.

Krawetz showed another image of al-Zawahiri from July 27, 2006, showing him seated in what appears to be a television studio. Krawetz said many people who saw this video were outraged that he could sitting in a television studio somewhere, yet the U.S. government couldn't find him.

Image analysis suggests that the studio and the various pictures positioned in the studio around him were added later. Again, a halo around al-Zawahiri suggests that he was shot in front of a monochromatic screen and pasted into a new background.