Re:I can haz ur eebay de-tails? (Score 1)

You might be mistaken. There have been talks for a while about combining these two types of files, a jar archive and a gif image. The jar format is based on the zip format. Zips have their header information in the end of the file. Gifs have their header information in the beginning of the file. One trick people have used to upload data files and secret messages to the internet is to simply append the zip file to the end of a gif file and upload it to an image host. When you download the image file from the image host, you get both the gif and the zip files. With a gif extension, the file will usually act like a gif and open up in image programs. With an archive program, you can open the zip file part. So, i believe the attack uses some of the trickery you describe, but also uses this type of trick to fool most detection programs. At least all of the detection programs that look for a valid image header.