The word “hacker” carries a sort of ambiguity. It commonly defines cybercriminals; actually, it should determine all people with an advanced understanding of computers and computer networks. “Cracker” should properly designate a hacker with malicious intentions within the wild west of the network’s environment.
However, “hacker” broadly indicates both criminals and informatics experts. In case of doubts, the correct meaning should be specified.
Beyond the distinction Hacker / Cracker, often misleading, the hackers could be classified based on their intentions, such as in the Western movies: the good ones wearing a white hat and the bad ones a black hat.
White Hat Hackers, also known as ethical hackers, are security hackers involved with the circumvention of systems after the authorisation of the system administrator. Companies usually pay them to discover vulnerabilities that should be adjusted so avoiding malicious hackers could exploit them.
Ethical hackers divide themselves into a red team (which simulates attacks to test the effectiveness of the network’s security) and a blue team (defensive security professionals who have to maintain defences). It is legal.
Black Hat Hackers, similar to crackers, are security hackers driven by malicious intentions. They violate computer security to steal, exploit, sell confidential data or cause damages. They are cybercriminals.
Grey Hat Hackers are security hackers who usually violate laws or ethical standards without malicious intentions. They can hack a computer system notifying the owner that their system is vulnerable. They can offer to correct the defect, or sometimes they share the information in private groups or chats. Even if they don’t have personal gain, unauthorised access is illegal.
Adrian Lamo was the most famous Grey Hat Hacker. He compromised the security systems of Yahoo and the New York Times (among others) without authorisation. Even if he offered to fix the security flaws free of charge, Lamo was sentenced in July 2004 to 2 years’ probation and ordered to pay $65,000 in restitution. He died in 2018 in mysterious circumstances (in his home, there were many bottles of pills, but experts didn’t identify a specific cause of the death).