Skilled computer users with malicious intents, they seek to compromise the security of a person or organization for personal gain. Blackhat hackers frequently specialize, for example in malware development, spam delivery, exploit discovery, DDoS attacks and more. Not all blackhat hackers use the malware they developed or the exploits they discover. Some just find them and sell the know-how to the highest bidder. Their favorite targets are financial information (such as credit card data or bank accounts), personal information (like email accounts and passwords), as well as sensitive company data (such as employee/client databases).