Denial of Service (DoS) backdoor attacks are a significant threat to computer systems. Backdoor attacks involve the installation of unauthorized software on a target system, which is then used to launch various attacks against other systems. In this paper, we explore several techniques that can be used to defeat DoS backdoor attacks, including access control, encryption, network monitoring, patch management, incident response planning, and employee education. Denial of Service (DoS) and Backdoor attacks are common types of cyber-attacks that can cause severe damage to computer systems and networks. DoS attacks aim to disrupt the availability of a system by overwhelming it with traffic or exploiting vulnerabilities, while Backdoor attacks provide attackers with unauthorized access to a system. This paper proposes a framework for defeating both types of attacks by implementing security measures at multiple levels, including the application layer, network layer, and host layer. The proposed framework involves techniques such as traffic filtering, load balancing, network segmentation, access control, and anomaly detection. At the application layer, the framework proposes implementing security measures such as input validation, error handling, and resource allocation to prevent DoS attacks. At the network layer, the framework recommends deploying firewalls, routers, and intrusion detection systems to filter traffic and detect anomalies. At the host layer, the framework proposes implementing security measures such as operating system hardening, patch management, and antivirus software to prevent Backdoor attacks. The proposed framework aims to provide a comprehensive approach to defeating DoS and Backdoor attacks by combining multiple security measures to provide a layered defense. By implementing the proposed framework, organizations can enhance the security of their computer systems and networks and prevent these types of attacks from causing damage.