The objective of this paper is to give an up-to-date terminology for and categorization of hackers on the Internet, and to characterize each category of hackers by their threat properties. To be able to prioritize defense efforts, security experts need an accurate taxonomy of attackers for the production of detailed and precise threat assessments. We take an existing taxonomy for hackers and update it to correspond to the terminology used by hackers and security experts. Also, the categories of hackers are updated to reflect the threat properties demonstrated in recent attacks, and each category is described in terms of motivations, capabilities, triggers, methods, and trends. The result is a current and detailed taxonomy usable in planning of digital defense efforts as well as in forensics after an attack has occurred.