Silverlight Resources

Recently T-Mobile USA put up a website T-Mobile Clue to tease the upcoming Samsung Vibrant cell phone. The website displayed a series of tiles covering an image. The tiles would slowly be removed and after four days, the image would be completely revealed. After realizing that the entire page was a Silverlight application, I decided to attempt to find the obscured image by examining the application using some of my reverse engineering skills picked up last semester.

I first examined the website's source code to find the actual Silverlight application which can be found here at the time of writing. Extracting this file would have been difficult if it weren't for Ubuntu assigning a zip icon for it. I simply double clicked the file and extracted the dlls.

I took the dlls and identified the one that was of importance (T-MobileClue.dll) and examined it in a PE Resource editor. I know realize that .NET Silverlight applications store resources differently than normal PE executables. Luckily there are applications similar to PE resource editors for .NET/Silverlight applications.

I used a program called Reflector to help go through the decompiled application. I quickly found by examining the source code that the obscured image to be revealed was the resource images/rebus.png. Reflector's resource browser quickly allowed me to open the resource. Sure enough this is the image that was revealed four days later. This was a few days ago so I do not feel bad revealing this information, but I will refrain from posting the rebus.png image here.

No comments: