Foreign adversaries have shown continued determination to influence the U.S. election — and there are signs their activity will intensify as Election Day nears, Microsoft said in a report Wednesday. Russian operatives are doubling down on fake videos to smear Vice President Kamala Harris’ campaign, while Chinese-linked social media campaigns are maligning down-ballot Republicans who are critical of China, the company’s threat intelligence arm said Wednesday. Meanwhile, Iranian actors who allegedly sent emails aimed at intimidating U.S. voters in 2020 have been surveying election-related websites and major media outlets, raising concerns they could be preparing for another scheme this year, the tech giant said. The report serves as a warning – building on others from U.S. intelligence officials – that as the nation enters this critical final stretch and begins counting ballots, the worst influence efforts may be yet to come. U.S. officials say they remain confident that election infrastructure is secure enough to withstand any attacks from American adversaries. Still, in a tight election, foreign efforts to influence voters are raising concern.