Live Updates –Russia Appears to Carry Out Hack Through System Used by U.S. Aid Agency

American officials have often been reluctant to respond to cyberaggression in kind, in part because the country’s own defenses are so inadequate. “Until we are confident in our own ability to deflect Russian cyberattacks, our actions will continue to be driven by concerns over what Putin will do,” said Kiersten Todt, the managing director of the Cyber Readiness Institute.

But both government officials and some experts argued that the hijacking of emails by the S.V.R. was such bread-and-butter stuff in the modern world of constant cyberconflict that it did not mark an escalation from SolarWinds. “It’s not obvious to me that this type of attack is over the red line,” said Robert Chesney, the director of the Strauss Center at the University of Texas at Austin.

In this case, Microsoft reported, the goal of the hackers was not to go after the aid agency itself. Instead, its motivation appeared to be to use emails purporting to be from the U.S. government to get inside groups that have revealed Russian disinformation campaigns, anti-corruption groups and those who have protested the poisoning, conviction and jailing of Russia’s best-known opposition leader, Alexei A. Navalny.

According to SecureWorks, an Atlanta cybersecurity firm tracking the attacks, the Russian hackers targeted the Atlantic Council and E.U. Disinfo Lab, which have both exposed several Russian disinformation campaigns.

Other targets included the Organization for Security and Cooperation in Europe, which has drawn Mr. Putin’s ire for criticizing the fairness of elections in Belarus and Ukraine; the Ukrainian Anti-Corruption Action Center, and Ireland’s Department of Foreign Affairs, according to SecureWorks.

Mr. Putin had previously described the Organization for Security and Cooperation in Europe as a “vile instrument of the West.” The fact that Russia took aim at these targets, not federal networks as it did with SolarWinds, suggested sanctions may have diverted Russia elsewhere.

“This may be Russia, and Putin specifically, saying, ‘Thanks for the sanctions — now we’re going to use America’s open and vulnerable networks for our own political purposes and vendettas,’” Ms. Todt said.