hacker
Refers to a person skilled in computer programming and security, often with a connotation of exploring or circumventing systems. In Japanese, it can carry both positive (skilled programmer) and negative (cracker) nuances depending on context.
He is known as an excellent hacker.
そのハッカーは企業のサーバーに侵入した。
The hacker broke into the company's server.
A hacker broke into the government's server.
The company's system was attacked by hackers.
Companies that handle personal data tend to become targets of hackers.