Russia, China, and other nation-states are wary of making false-flag cyberattacks, which involve conducting attacks pinned on another country, The Register
"It's one of the last rules of the playground that a modern nation may not want to break because they don't want everyone doing false flags," said Mandiant CEO Kevin Mandia at Vanderbilt University's Summit on Modern Conflict and Emerging Threats.
While National Security Agency Cybersecurity Director Rob Joyce noted the difficulty of achieving complete confidence in attributing cyberattacks to a certain nation-state or cybercrime group, authorities have been looking at established tactics, techniques, and procedures of threat actors, as well as NSA and FBI intelligence.
"When you get a White House podium statement that X did Y, like we did with with everything from Sony Pictures to NotPetya
, that's 100 percent" confidence in the attribution. When you see the US government come out and give attribution, that is a super high level of confidence," said Joyce.