text: Description Criminals who intentionally enter computer networks with malicious intent are known as "black hat hackers". They may distribute malware that steals data (particularly login credentials), financial information, or personal information (such as passwords or credit card numbers). This information is often sold on the dark web. Malware can also be used to hold computers hostage or destroy files. Some hackers may also modify or destroy data in addition to stealing it. While hacking has become an important tool for governments to gather intelligence, black hats tend to work alone or with organized crime groups for financial gain.
  Black hat hackers may be novices or experienced criminals. They are usually competent infiltrators of computer networks and can circumvent security protocols. They may create malware, a form of software that enables illegitimate access to computer networks, enables the monitoring of victims' online activities, and may lock infected devices. Black hat hackers can be involved in cyber espionage or protests in addition to pursuing personal or financial gain. For some hackers, cybercrime may be an addictive experience.
  History
  One of the earliest and most notorious black hat hacks was the 1979 hacking of The Ark by Kevin Mitnick. The Ark computer system was used by Digital Equipment Corporation (DEC) to develop the RSTS/E operating system software.
  The WannaCry ransomware attack in May 2017 is another example of black hat hacking. Around 400,000 computers in 150 countries were infected within two weeks. The creation of decryption tools by security experts within days limited the extortion payments to approximately $120,000, or slightly more than 1% of the potential payout.