Both Robert Mueller’s report and a previous indictment of 12 Russian agents confirmed Russians also targeted private vendors that provided election software. The Russians successfully breached at least one company, its name redacted in the reports, “and installed malware on the company network”, according to the Mueller report.

Intelligence agencies expect cyber attacks from Russia, China and other nations against America’s democracy to continue in 2020.

https://www.theguardian.com/us-news/2019/apr/22/us-voting-machine-private-companies-voter-registration