What term describes the performance of a totally wrongful and unlawful act?

The term that describes the performance of a totally wrongful and unlawful act is malfeasance. This concept refers specifically to the act of performing a lawful act in a wrongful or unlawful manner, which can lead to harm or injury. In a legal context, malfeasance is often associated with a breach of duty, where an individual or professional acts in a way that is not just negligent but intentionally harmful or unlawful.

In contrast, malpractice typically refers to professional misconduct or lack of skill in a professional setting, and it does not necessarily involve the inherently unlawful nature that malfeasance implies. Misfeasance involves performing a lawful act in a negligent way, and nonfeasance refers to the failure to act when there is a duty to do so. Therefore, malfeasance precisely captures the essence of executing an act that is not only wrong but also illegal, making it the correct term for the situation described.