Ransomware attacks have become more prevalent, sophisticated and organized. Ransomware is a catch-all term associated with revenue-generating malicious software that encrypts and/or immobilizes the target system or data until payment is rendered. The ransom is typically paid via anonymous means to obscure the payee.  

This article addresses the history and evolution of ransomware and the current state of ransomware attacks, approaches and targets. Additionally, current ransomware practices related to the commercialization of tools and processes, structure and nature of attacks are highlighted, and emerging trends in ransomware development, delivery and targeting are explored.