US officials and private sector experts investigating the massive data breach that has rocked Washington increasingly believe the attackers were ultimately discovered because they took a more aggressive "calculated risk" that led to a possible "unforced error" as they tried to expand their access within the network they had penetrated months earlier without detection, according to a US official and two sources familiar with the situation.


원문출처 : https://www.cnn.com/2020/12/23/politics/hack-unforced-error-discovery/index.html