President Trump has yet to say anything about the attack.
Echoing the government’s warning, Microsoft said Thursday that it had identified 40 companies, government agencies and think tanks that the suspected Russian hackers, at a minimum, had infiltrated. Nearly half are private technology firms, Microsoft said, many of them cybersecurity firms, like FireEye, that are charged with securing vast sections of the public and private sector.
“It’s still early days, but we have already identified 40 victims — more than anyone else has stated so far — and believe that number should rise substantially,” Brad Smith, Microsoft’s president, said in an interview on Thursday. “There are more nongovernmental victims than there are governmental victims, with a big focus on I.T. companies, especially in the security industry.”
The Energy Department and its National Nuclear Security Administration, which maintains the American nuclear stockpile, were compromised as part of the larger attack, but its investigation found the hack did not affect “mission-essential national security functions,” Shaylyn Hynes, a Department of Energy spokeswoman, said in a statement.
“At this point, the investigation has found that the malware has been isolated to business networks only,” Ms. Hynes said. The hack of the nuclear agency was reported earlier by Politico.
Officials have yet to publicly name the attacker responsible, but intelligence agencies have told Congress that they believe it was carried out by the S.V.R., an elite Russian intelligence agency. A Microsoft “heat map” of infections shows that the vast majority — 80 percent — are in the United States, while Russia shows no infections at all.