The U.S. government is still struggling to understand the full scope of the SolarWinds hack as well as a more recent compromise of Microsoft's email servers, as the head of U.S. Cyber Command said the government struggles to track foreign adversaries who launch attacks using U.S. infrastructure. National Security Agency Director and CYBERCOM Commander Gen. Paul Nakasone, testifying before the Senate Armed Services Committee today , said the recent hacks were "a scope, a scale, a level of sophistication that...