Bloomberg News:
Russia’s cyberattack on the U.S. electoral system before Donald Trump’s election was far more widespread than has been publicly revealed, including incursions into voter databases and software systems in almost twice as many states as previously reported.

Details of the wave of attacks, in the summer and fall of 2016, were provided by three people with direct knowledge of the U.S. investigation into the matter. In all, the Russian hackers hit systems in a total of 39 states, one of them said.