White Hat hackers

White Hat hackers are also known as Ethical Hackers. White Hat hackers are the good guys of the hacker world. They’ll help you remove a virus or PenTest a company. Most White Hat hackers hold a college degree in IT security or computer science and must be certified to pursue a career in hacking. The most popular certification is the CEH (Certified Ethical Hacker) from the EC-Council.

They are not a dangerious hackers :) they always trying to help.