MakeLoaders is an applet which creates its own subclasses of AppletClassLoader and puts them to use. It uses the abstract class OuterLoader and the class InnerLoader to introduce a novel loadClass method, download the class Dummy from an unexpected location, and run code from the downloaded class. (The version of Dummy in the expected location is not touched.) The applet works with Netscape's Communicators 4.04 and 4.05.
Note: Due to the simplicity of its loadClass method, the applet may fail to download Dummy.class properly on occasion. If so, you might try reloading it. You can also grab the source code, experiment with it yourself, and easily improve it. (To compile it, you will need to have the Communicator's classes in your CLASSPATH.) The main point here is that applets can create and use subclasses of AppletClassLoader. This paves the way for all sorts of attack applets.