The hackers successfully infiltrated the election campaign computer of David Min, a Democratic candidate for the House of Representatives who was later defeated in the June primary for California’s 45th Congressional district.

The incident, which has not been previously reported, follows an article in Rolling Stone earlier this week that the FBI has also been investigating a cyber attack against Hans Keirstead, a California Democrat. He was defeated in a primary in the 48th Congressional district, neighboring Min’s…

While both Min and Keirstead later lost to other primary challengers from their own party, the two closely-watched races are considered critical, competitive battlegrounds as the Democrats seek to win back Congress from Republicans in November.