The Russians, she said, sought to “undermine our democracy” through cyberattacks on Democratic targets. She said the hacking into the Democratic National Committee and into the emails of her campaign chairman, John D. Podesta, were a result of Mr. Putin’s “personal beef” against her, pointing to her accusation that Russia’s 2011 parliamentary elections were rigged.

“Putin publicly blamed me for the outpouring of outrage by his own people, and that is the direct line between what he said back then and what he did in this election,” Mrs. Clinton said.

They were her first public remarks since widespread reports that the Russian government was behind the cyberattacks on the Democratic National Committee and Mr. Podesta, with the goal of influencing the election.

“Make no mistake, as the press is finally catching up to the facts, which we desperately tried to present to them during the last months of the campaign,” Mrs. Clinton told the group, which collectively poured roughly $1 billion into her effort. “This is not just an attack on me and my campaign, although that may have added fuel to it. This is an attack against our country. We are well beyond normal political concerns here. This is about the integrity of our democracy and the security of our nation.”