AI is fueling a surge in cyberattacks, with the average breach now costing SMBs more than $250,000. In this issue of the HBR Executive Agenda, cybersecurity expert Daniel Dobrygowski says SMBs can dramatically reduce their exposure by nailing the basics, taking inventory of what’s connected to their systems, using AI to stress-test their own defenses, vetting vendors carefully, and treating cybersecurity as a CEO-level priority.