What are experts in technology who use their knowledge to break into computers and networks, for profit or just as a challenge known as?

Hacker

Explanation:

Hacker -

It refers to the computer software expert, who is responsible to break into the unauthorized networks or computer, is referred to as a hacker.

The hacker is skilled with exceptional computer and computer software knowledge.

Hacking is an illegal practice, as the person is able to access some confidential and personal data and information of any other person or organisation.

Hence, from the given information of the question,

The correct term is hacker.