Sandworm is a nonfiction cybersecurity book that investigates the activities of the Sandworm hacking group, widely believed to be linked to Russian military intelligence. Through detailed reporting and interviews, Andy Greenberg traces the group's involvement in major cyber incidents, including attacks on Ukraine's power grid, the NotPetya malware outbreak, and other operations targeting governments, businesses, and critical infrastructure around the world. The book explains how cyber warfare has evolved into a powerful tool of geopolitical conflict, highlighting the growing risks posed by state-sponsored cyber operations and the challenges of defending against sophisticated digital attacks.