Backdoor attacks involve an individual

Exploiting vulnerabilities in the design or implementation of websites through hacking techniques, code injection, scripting $($altering code$),$ and social engineering.

Exploiting an opening in an operating system, application, or computer system that is not protected by an organization$$s security measures.

Flooding a network or server with digital traffic, thus making it unavailable to users.

Spreading malicious software through email attachments to take over computer systems.