Two groups of Russian hackers burrowed into the Democratic National Committee’s servers and spent months stealing information on Donald Trump, the Republican Party’s presumptive presidential nominee, according to Crowdstrike. The security firm identified “two sophisticated adversaries on the network,” noted CTO Dmitri Alperovitch, dubbed “Cozy Bear” and “Fancy Bear.” They are “some of the best adversaries [among the] groups we encounter on a daily basis,” he said. “Their tradecraft is superb, operational security second to none.”