Which of the following practices come in the category of denial of service attack? Each correct answer represents a complete solution. Choose three.

A backdoor attack is a method of establishing covert unauthorized access that bypasses normal authentication - it is an intrusion technique aimed at persistence, not at denying service.

Disrupting services to a specific computer is the core definition of a DoS attack, directly targeting availability and preventing legitimate users from accessing the system or service.

Sending thousands of malformed packets to consume bandwidth is a classic DoS flooding technique that exhausts network resources and denies service to legitimate traffic.

An ICMP flood (ping flood) sends massive volumes of ICMP echo requests to saturate the target's network interface and processing capacity, which is a recognized DoS technique.