INTRUSION WINDOWS XP BY BACKDOOR TOOL.

Sometimes operating system designer personal deliberately create a hole in the security of the system. This hole or backdoor allows them later to take control of the system. Attackers who have compromised a system to ease their subsequent return to the system often install backdoors. This paper presents a tool for intrusion operating system (Windows XP) by using one of the system port the main reason for using this port to fabricate the firewall and the administrator on the server computer, where this tool can work by placed intrusion program into chess game then attach this game with email after attachment then send this email to any computer server. Tiny firewall used to test the proposed tool and check if intrusion occurred. 1-Introduction A hackers use several techniques to break into a computer or network. One-way hacker programmer creates a backdoor (trap door), which is an entrance into a system that penetrates security. A programmer can intentionally leave backdoors in place, sometimes for legitimate reasons, such as giving service techs a way to check the system or application. A Backdoor is like a hidden secret-word entrance, the programmer knows the key to this door, but no body else even knows the door is there. Backdoor is a mechanism surreptitiously introduced into a computer system to facilitate unauthorized access to the system. While backdoors can be installed for accessing a variety of services, of particular interest for network security are ones that provide interactive access. These are often installed by attackers who have compromised a system to ease their subsequent return to the system [2]. 2-Backdoor Functionality The backdoor for most intruders provide two or three main functions: Be able to get back into a machine even if the administrator tries to secure it, e.g., changing all the passwords. Be able to get back into the machine with the least amount of visibility. Most backdoors provide a way to avoid being logged and many times the machine can appear to have no one online even while an intruder is using it. Be able to get back into the machine with the least amount of time. Most Intruders want to easily get back into the machine without having to do all the work of exploiting a hole to gain access [3]. Backdoor are two–part program (server and client application). A small, virtually unnoticeable server component is installed on the victim’s pc, which the attacker accesses remotely through a convenient client GUI (Graphical User Interface). The attacker uses the server as a bidirectional surreptitious channel to sidestep existing security mechanisms and access the compromised system remotelyall without the victim’s knowledge. Two TCP (Transmission Control Protocol) connections are established when the server application is accessed by an attacker using the client application. The attacker client sends commands via a connection to port number of the victim machine. The victim server transmits data in response via a connection to port number of the victim machine [4]. 3-Intrusion by port When a process on one host wants to communicate with a process on a different host, it identifies itself to the TCP/IP (Transmission Control Protocol/ Internet Protocol) protocol suite via one or more ports. A port identifies the application that is using the UDP (User Datagram Protocol) or TCP