Office Of Personnel Management
Revealed in June, the two breaches of the Office of Personnel Management have snowballed into what is arguably one of the biggest cyberattacks in history. The larger of the two breaches, affecting 21.5 million federal workers, was discovered in late May after a separate, unrelated breach hit the agency in April, exposing the personnel data of 4.2 million individuals. While the actors behind the attack haven't officially been announced, reports have tied the attacks to China-based hackers. While details are still emerging about the extent of the attacks and their effect on millions of federal workers, some of the implications have already begun with the resignation of OPM Director Katherine Archuleta.