Attempted Hack of R.N.C. and Russian Ransomware Attack Test Biden The breach of a Republican National Committee contractor, also linked to Russia, and the global ransomware attack occurred weeks after a U.S.-Russian summit. At their summit in Geneva last month, President Biden said he had warned his Russian counterpart, Vladimir V. Putin, of red lines in the cyber arena.Credit...Doug Mills/The New York Times July 6, 2021Updated 8:44 p.m. ET Russian hackers are accused of breaching a contractor for the Republican National Committee last week, around the same time that Russian cybercriminals launched the single largest global ransomware attack on record, incidents that are testing the red lines set by President Biden during his high-stakes summit with President Vladimir V. Putin of Russia last month.