State-backed hackers from China have targeted staffers working on the U.S. presidential campaign of Joe Biden, a senior Google security official said Thursday. The same official said Iranian hackers had also recently targeted email accounts belonging to President Donald Trump's campaign staff.
The announcement, made on Twitter by the head of Google's Threat Analysis Group, Shane Huntley, is the latest indication of the digital spying routinely aimed at top politicians of all stripes.
Huntley said there was "no sign of compromise" of either campaign.
Iranian attempts to break into Trump campaign officials' emails have been documented before. Last year, Microsoft Corp announced that a group often nicknamed Charming Kitten had tried to break into email accounts belonging to an unnamed U.S. presidential campaign that sources identified as Trump's.
Earlier this year, the threat intelligence company Area1 said that Russian hackers had targeted companies tied to a Ukrainian gas firm where Biden's son once served on the board.
Google declined to offer details beyond Huntley's tweets, but the unusually public attribution is a sign of how sensitive Americans have become to digital espionage efforts aimed at political campaigns.
The Trump and Biden campaigns did not immediately return messages. The Chinese Embassy in Washington did not immediately respond to requests for comment. The Iranian mission to the United Nations in New York did not immediately respond to messages.