Mining cryptocurrencies such as Bitcoin is a data-intensive, energy-draining, and expensive undertaking. So cybercriminals have learned ways to spread the work, as it were, by farming out the solving of complex mathematical problems to unsuspecting computers used in smartphones, desktops, and servers. One method is to trick the user into downloading malware that works in the background to verify the cybercurrency transactions. Even the smartest companies are vulnerable. In 2018, Google was infected by cryptominers who used malware to jack into the processing power of YouTube’s ad network.