Cryptomining malware is malicious code that takes over a computing device's resources so an attacker can use the device's processing power to track and verify cryptocurrency transactions in a distributed ledger. In digital currencies like Bitcoin, the verification process is known as mining and it can be financially profitable for the agents who engage in it.
Cryptomining malware most often infects a computer when a user unknowingly downloads malware. Attackers typically embed infected code in other programs or files in order to bypass a system's security. Because cryptomining software runs in the background, a user might not realize they have been the victim of an attack until they experience a graceful degradation of service. To defend against this type of attack, security experts recommend individuals keep software up-to-date and network administrators perform regular penetration tests.
The act of infecting a computing device with malicious code is known as cryptojacking. A large-scale cryptojacking attack took place in February 2019, when a virus called CookieMiner was launched against Apple products. Large-scale attacks have also be aimed at networks and servers, targeting multiple machines at once.