Sandworm: A New Era of Cyberwar and the Hunt for the Kremlin’s Most Dangerous Hackers by Andy Greenberg Doubleday, 348 pp., $28.95

In mid-October, a cybersecurity researcher in the Netherlands demonstrated, online, as a warning,* the easy availability of the Internet protocol address and open, unsecured access points of the industrial control system—the ICS—of a wastewater treatment plant not far from my home in Vermont. Industrial control systems may sound inconsequential, but as the investigative journalist Andy Greenberg illustrates persuasively in Sandworm: A New Era of Cyberwar and the Hunt for the Kremlin’s Most Dangerous Hackers, they have become the preferred target of malicious actors aiming to undermine civil society. A wastewater plant, for example, removes contaminants from the water supply; if its controls were to be compromised, public health would be, too.

That Vermont water treatment plant’s industrial control system is just one of 26,000 ICS’s across the United States, identified and mapped by the Dutch researcher, whose Internet configurations leave them susceptible to hacking. Health care, transportation, agriculture, defense—no system is exempt. Indeed, all the critical infrastructure that undergirds much of our lives, from the water we drink to the electricity that keeps the lights on, is at risk of being held hostage or decimated by hackers working on their own or at the behest of an adversarial nation. According to a study of the United States by the insurance company Lloyd’s of London and the University of Cambridge’s Centre for Risk Studies, if hackers were to take down the electric grid in just fifteen states and Washington, D.C., 93 million people would be without power, quickly leading to a “rise in mortality rates as health and safety systems fail; a decline in trade as ports shut down; disruption to water supplies as electric pumps fail and chaos to transport networks as infrastructure collapses.” The cost to the economy, the study reported, would be astronomical: anywhere from $243 billion to $1 trillion. Sabotaging critical infrastructure may not be as great an existential threat as climate change or nuclear war, but it has imperiled entire populations already and remains a persistent probability.

From 2011 to 2013 Iranian hackers breached the control system of a small dam outside of New York City. Around the same time, they also broke into the servers of banks and financial firms, including JPMorgan Chase, American Express, and Wells Fargo, and besieged them for 144 days. The attacks were in retaliation for the Stuxnet virus, unleashed in 2010, which caused the destruction of nearly a thousand centrifuges at Iran’s largest uranium enrichment facility. Though neither the United States nor Israel took credit for the attack, both countries are widely believed to have created and deployed the malware that took over the facility’s automated controllers and caused the centrifuges to self-destruct. The attack was intended to be a deterrent—a way to slow down Iran’s nuclear development program and force the country to the negotiating…