Mirai (未来 in original Japanese, lit. meaning "the future") is malware that turns computer systems running the Linux operating system into remotely controlled "bots", that can be used as part of a botnet in large-scale network attacks. It primarily targets online consumer devices such as remote cameras and home routers. The Mirai botnet has been used in some of the largest and most disruptive distributed denial of service (DDoS) attacks, including an attack on 20 September 2016 on computer security journalist Brian Krebs's web site, an attack on French web host OVH and the October 2016 Dyn cyberattack.

The source code for Mirai has been published in hacker forums as open-source. Since the source code was published, the techniques have been adapted in other malware projects.