Figuring out who exactly is responsible for a cyberattack is an inexact science, but advances in machine learning and years of data-gathering on hacks are making it easier than ever for law-enforcement officials and cybersecurity specialists to name the likely culprits.
Governments around the world, once reluctant to point fingers after a cyberattack, have issued a string of indictments in recent months related to several high-profile breaches. On Thursday, the U.S. Justice Department charged seven Russian military officers...