The NGSSoftware team has found a way to embed a Java applet within a GIF; the hybridized file is referred to as a GIFAR. Just to make it clear, this is a file extension of convenience and not the ...

To the Web server, the file looks exactly like a .gif file, however a browser’s Java virtual machine will open it up as a Java Archive file and then run it as an applet.

The GIF part fools the browser into opening it as a picture and trusting the content. The reality is, the Java VM recognizes the JAR part and automatically runs it.