Trojan-Downloader.JAVA.Openstream

I am writing an applet using JBuilder, to upload large files to a server by chopping them into sections and sending each section separately.

Unfortunately my Kaspersky anti-virus identifies the basic applet as this Trojan-Downloader.Java.Openstream.

I doubt if JBuilder4 is adding malicious code to the applet, so it is simply the following code ( not even working yet, just a few ideas typed in)

How to I prevent an applet being identified as this trojan?

package applet2;

import java.awt.*;
import java.awt.event.*;
import java.applet.*;
import javax.swing.*;
/**
* Title: Uploader for Multihandler
* Description: Large file uploader
* Copyright: Copyright (c) 2004
* Company: Peter Thomson
* @author Peter Thomson
* @version 1.0
*/


public class Applet1 extends JApplet {
boolean isStandalone = false;
String var0;
String var1;
public String uploadfilename;
JFileChooser jFileChooser1 = new JFileChooser();
Box box1;
TextField textField1 = new TextField();
TextField textField2 = new TextField();
Button Uploadbutton = new Button();
/**Get a parameter value*/
public String getParameter(String key, String def) {
return isStandalone ? System.getProperty(key, def) :
(getParameter(key) != null ? getParameter(key) : def);
}

/**Construct the applet*/
public Applet1() {
}
/**Initialize the applet*/
public void init() {
try {
var0 = this.getParameter("param0", "");
}
catch(Exception e) {
e.printStackTrace();
}
try {
var1 = this.getParameter("param1", "");
}
catch(Exception e) {
e.printStackTrace();
}
try {
jbInit();
}
catch(Exception e) {
e.printStackTrace();
}
}
/**Component initialization*/
private void jbInit() throws Exception {
box1 = Box.createHorizontalBox();
this.setSize(new Dimension(400,300));
textField1.setText("None selected");
jFileChooser1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(ActionEvent e) {
jFileChooser1_actionPerformed(e);
}
});
textField2.setText("You have chosen");
Uploadbutton.setLabel("Upload file");
Uploadbutton.addMouseListener(new java.awt.event.MouseAdapter() {
public void mouseClicked(MouseEvent e) {
Uploadbutton_mouseClicked(e);
}
});
this.getContentPane().add(jFileChooser1, BorderLayout.SOUTH);
this.getContentPane().add(box1, BorderLayout.CENTER);
box1.add(textField2, null);
box1.add(textField1, null);
this.getContentPane().add(Uploadbutton, BorderLayout.EAST);
}
/**Start the applet*/
public void start() {
}
/**Stop the applet*/
public void stop() {
}
/**Destroy the applet*/
public void destroy() {
}
/**Get Applet information*/
public String getAppletInfo() {
return "Applet Information";
}
/**Get parameter info*/
public String[][] getParameterInfo() {
String[][] pinfo =
{
{"param0", "String", "url"},
{"param1", "String", ""},
};
return pinfo;
}

//static initializer for setting look & feel
static {
try {
//UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
//UIManager.setLookAndFeel(UIManager.getCrossPlatformLookAndFeelClassName());
}
catch(Exception e) {
}
}

void jFileChooser1_actionPerformed(ActionEvent e) {
uploadfilename=jFileChooser1.getSelectedFile().getPath();
textField1.setText(jFileChooser1.getSelectedFile().getName());

System.out.println("action taken here" + uploadfilename );
}

void Uploadbutton_mouseClicked(MouseEvent e) {

upload_file_name newup=new upload_file_name(uploadfilename);

System.out.println("action taken here " + uploadfilename );
}
}