According to the dictionary meaning, a hacker is any person who usually has extraordinary computer skills and uses his knowledge to gain unauthorized access to target systems. However, in practice there are several categories of hackers, which are classified based on the intent and motive behind hacking and the method used for hacking.
Black Hat Hackers –
These are mainly individuals with extraordinary computing skills but performing activities that are malicious or destructive in nature. They are also sometimes referred as crackers .
Famous Black Hat Hackers are: Julian Assange, Kevin Mitnick, Albert Gonzalez, Kevin Poulsen and Robert Tappan Morris.
White Hat Hackers –
They are individuals with relevant hacking skills who utilize their knowledge for defensive purposes (for example, to protect organizations from hacking attacks). They are also known as security analysts .
Famous White Hat Hackers are: Kevin Mitnick, Linus Torvalds, Charlie Miller, Jeff Moss, Dan Kaminsky, Richard M. Stallman, Greg Hoglund, Tsutomu Shimomura, Marc Maiffret and Tim Berners-Lee
Gray Hat Hackers –
These are individuals who work offensively as well as defensively at various times.
Famous Gray Hat Hackers are: Adrian Lamo, Vladimir Levin, Albert Gonzalez, Gary McKinnon, Kelvin Poulson, Syrian Electronic Army, Anonymous Group, Astra and Max Ray Butler
Suicide Hackers –
These are individuals who aim to attack and bring down critical infrastructure and aren’t worried at all about the consequence or the punishment they might face for their act.
Famous Suicide Hackers are: Robert Tappan Morris and Julian Assange
These are mainly unskilled and novice hackers who use tools and scripts developed by others to hack into systems. They don’t possess knowledge and skills as compared to real hackers.
Spy Hackers –
These are individuals who are specifically hired by organizations to spy and penetrate to get trade secrets and confidential data from competitors.
Cyber Terrorists –
These are individuals with a wide array of skills who are motivated by religious or political agenda to launch massive attacks against computer networks and systems.
State-Sponsored Hackers –
These are individuals who work for government agencies to get top-secret information from rival nations and governments.