Ransomware

Ransomware is malware in which information on a victim's computer is encrypted and payment is demanded before granting them access. Ransomware is one of the most trending and high-return types of crimeware. It has attracted an enormous amount of media coverage in the past two years, mainly because of WannaCry, NotPetya, and Locky. WannaCry ransomware was spread rapidly across a number of systems worldwide in May 2017. It targeted several high-profile organizations including the UK's National Health Service, Spanish telephone giant Telefonica, French automobile leader Renault, US leading logistics company FedEx, Japanese firm Hitachi, and many more.  

The ransomware author hosts the service over the dark web, which allows any buyer to create and modify the malware.

The dark web is a part of the internet that can't be fetched with a search engine but needs a special type of anonymity browser called Tor. In other words, the dark web carries unindexed data that's not available to search engines. The Tor browser basically routes the user information through a series of proxy servers that makes user identity unidentifiable and untraceable. Dark websites look similar to ordinary websites, but there are some differences in the naming structure. Dark websites don't have a top-level domain (TLD) such as .com or .net or .co; rather, they just use websites that end with .onion.