Cryptocurrency miners that infect the computers of unsuspecting users essentially operate according to the same business model as ransomware programs. Cryptominers usually find their way onto user computers and corporate machines along with adware, hacked games, and other pirated content. A separate category of cybercriminals are those who target not private computers, but the servers of large companies, for which the infection process is considerably more resource-intense. Hidden mining software was very popular among botnet owners, as confirmed by our statistics on files downloaded by zombie networks: Q1 2018 saw a boom in cryptominers.”]
Source: https://securelist.com/kaspersky-security-bulletin-2018-story-of-the-year-miners/89096/