The United States expanded its hunt on Thursday for Russia’s most elite cyberwarriors, indicting five members of the country’s military intelligence agency for attacks on Ukraine and American companies in the run-up to the invasion of Ukraine in 2022.

The State Department and American allies also offered a reward of up to $60 million for their arrests; the reward for Osama bin Laden and other leaders of Al Qaeda after the Sept. 11, 2001, attacks was $25 million.

The attacks, known as “Whisper Gate,” on Ukraine’s government agencies, NATO countries and American firms were essentially the opening salvos in the invasion of Ukraine. They were intended to cripple the government, bring down a major satellite communications network and scare off NATO nations from coming to Kyiv’s aid. But the attacks were countered by U.S. Cyber Command and firms like Microsoft, Google and Amazon, who moved the operations of the Ukrainian government to the cloud and kept the country running in a remarkable digital defense operation.

“The Whisper Gate attack in January of 2022 could be considered the first shot of the war,” said William J. DelBagno, the F.B.I.’s special agent in charge of the Baltimore field office. “The cybercriminals sent a message with their malware to, quote, be afraid and expect the worst. A month later, Russia physically invaded the country.”

In the hours before the invasion in February 2022, it was Microsoft’s warning to the White House about a gathering digital storm, meant to blind Ukraine, that provided another warning that tanks were getting ready to roll.

The Justice Department announced they had charged five members of the Russian military intelligence service known as the G.R.U. in connection with the attack, which targeted Ukrainian critical infrastructure including financial systems, emergencies services, health care, education and other sectors.