Mozilla Firefox 1.x before 1.5 and 1.0.x before 1.0.8, Mozilla Suite before 1.7.13, and SeaMonkey before 1.0 allows remote attackers to trick users into downloading and saving an executable file via an image that is overlaid by a transparent image link that points to the executable, which causes the executable to be saved when the user clicks the "Save image as..." option.  NOTE: this attack is made easier due to a GUI truncation issue that prevents the user from seeing the malicious extension when there is extra whitespace in the filename.