What is 'salary thief'?

Hello, I am curious about the meaning of the term 'salary thief.' I would like to know which of the following cases is correct. First, someone who is employed but secretly plays games, shops online, and chats with others during work hours, while not doing any actual work. Second, a person whose father is the company president, and they receive a salary without working at the company. Third, a person who has a friend in the HR department, and they receive a salary from the company without actually working. Which of these three situations best fits the expression 'salary thief'? I would love to hear your opinions. Thank you.