WASHINGTON -- While senior Trump administration officials said this week that Iran has been actively interfering in the presidential election, many intelligence officials said they remained far more concerned about Russia, which in recent days has hacked into state and local computer networks in breaches that could allow Moscow broader access to U.S. voting infrastructure.
The discovery of the hacks came as U.S. intelligence agencies, infiltrating Russian networks themselves, have pieced together details of what they believe are Russia's plans to interfere in the presidential race in its final days or immediately after the election Nov. 3.
Officials did not make clear what Russia planned to do, but they said its operations would be intended to help President Donald Trump, potentially by exacerbating disputes around the results, especially if the race is too close to call.
There is no evidence that the Russians have changed any vote tallies or voter registration information, officials said. They added that the Russian-backed hackers had penetrated the computer networks without taking further action, as they did in 2016. But U.S. officials expect that if the presidential race is not called on election night, Russian groups could use their knowledge of the local computer systems to deface websites, release nonpublic information or take similar steps that could sow chaos and doubts about the integrity of the results, according to U.S. officials briefed on the intelligence.
Some U.S. intelligence officials view Russia's intentions as more significant than the announcement Wednesday night by the director of national intelligence, John Ratcliffe, that Iran has been involved in the spreading of faked, threatening emails, which were made to appear as if they came from the Proud Boys, a right-wing extremist group.
The fake emails appeared aimed at intimidating voters. Ratcliffe said the intent was to hurt Trump in the contest against former Vice President Joe Biden.
Officials briefed on the intelligence said Ratcliffe had accurately summarized the preliminary conclusion about Iran. But Iran's hackers may have accomplished that mission simply by assembling public information and then routing the threatening emails through Saudi Arabia, Estonia and other countries to hide their tracks. One official compared the Iranian action as single A baseball, while the Russians are major leaguers.
A spokesman for Iran's mission to the United Nations, Alireza Miryousefi, denied Tehran had anything to do with the alleged voter intimidation.
"Unlike the U.S., Iran does not interfere in other country's elections," Miryousefi wrote on Twitter. "The world has been witnessing U.S.' own desperate public attempts to question the outcome of its own elections at the highest level."
Nonetheless, both the Iranian and the Russian activity could pave the way for "perception hacks," which are intended to leave the impression that foreign powers have greater access to the voting system than they really do. Federal officials have warned for months that small breaches could be exaggerated to prompt inaccurate charges of widespread voter fraud.
House Speaker Nancy Pelosi, D-Calif., and Rep. Adam Schiff, D-Calif. and chairman of the House intelligence committee, said the "disturbing" threats cut to the heart of the right to vote.
"We cannot allow voter intimidation or interference efforts, either foreign or domestic, to silence voters' voices and take away that right," they said in a statement.
Officials say Russia's ability to change vote tallies nationwide is limited.
A hacking group believed to be operating at the behest of Russia's Federal Security Service, the the successor agency to the Soviet-era KGB, has infiltrated multiple state and local computer networks in recent weeks, according to officials and researchers. The group, known to private researchers as Energetic Bear or Dragonfly, has hacked into U.S. nuclear, water and power plants and airports before. While it has stopped short of shutting them down, the group is considered to be among Russia's most formidable.
The Russian hackers were able to get inside some election administrators' systems and had access to voting information.
The officials fear that Russia could change, delete or freeze voter data, making it harder for voters to cast ballots, invalidating mail-in ballots or creating enough uncertainty to undermine election results.
Information for this article was contributed by Julian E. Barnes, Nicole Perlroth and David E. Sanger of The New York Times; and by Eric Tucker, Frank Bajak, Christina A. Cassidy, Michael Balsamo, Colleen Long, Zeke Miller, Amir Vahdat and Jon Gambrell of The Associated Press.