That’s made ransomware popular with criminal hackers, who often demand payment in hard-to-trace cryptocurrencies. Some particularly vicious strains, such as WannaCry, have compromised hundreds of thousands of computers (see “The WannaCry Ransomware Attack Could’ve Been a Lot Worse”). One big target in 2018 will be cloud computing businesses, which house mountains of data for companies. Some also run consumer services such as e-mail and photo libraries. The biggest cloud operators, like Google, Amazon, and IBM, have hired some of the brightest minds in digital security, so they won’t be easy to crack. But smaller companies are likely to be more vulnerable, and even a modest breach could lead to a big payday for the hackers involved.

The weaponization of AI

This year will see the emergence of an AI-driven arms race. Security firms and researchers have been using machine-learning models, neural networks, and other AI technologies for a while to better anticipate attacks, and to spot ones already under way. It’s highly likely that hackers are adopting the same technology to strike back. “AI unfortunately gives attackers the tools to get a much greater return on their investment,” explains Steve Grobman, chief technology officer at McAfee.

An example is spear phishing, which uses carefully targeted digital messages to trick people into installing malware or sharing sensitive data. Machine-learning models can now match humans at the art of crafting convincing fake messages, and they can churn out far more of them without tiring. Hackers will take advantage of this to drive more phishing attacks. They’re also likely to use AI to help design malware that’s even better at fooling “sandboxes,” or security programs that try to spot rogue code before it is deployed in companies' systems.

Cyber-physical attacks

More hacks targeting electrical grids, transportation systems, and other parts of countries’ critical infrastructure are going to take place in 2018. Some will be designed to cause immediate disruption (see “A Hack Used to Plunge Ukraine into Darkness Could Still Do Far More Damage”), while others will involve ransomware that hijacks vital systems and threatens to wreak havoc unless owners pay swiftly to regain control of them. During the year, researchers—and hackers—are likely to uncover more chinks in the defenses of older planes, trains, ships, and other modes of transport that could leave them vulnerable.

Mining cryptocurrencies

Hackers, including some allegedly from North Korea, have been targeting holders of Bitcoin and other digital currencies. But the theft of cryptocurrency isn’t the biggest threat to worry about in 2018; instead, it’s the theft of computer processing power.