Christopher Krebs, former director of the Cybersecurity and Infrastructure Security Agency, appeared on Capitol Hill on Dec. 16. Krebs told NPR that Russian intelligence is responsible for the massive hack that’s affected the U.S. government.

WASHINGTON, DC – DECEMBER 16: Chris Krebs, former director of the Cybersecurity and Infrastructure Security Agency, gives an opening statement during a Senate Homeland Security and Governmental Affairs Committee hearing to discuss election security and the 2020 election process on December 16, 2020 in Washington, DC. U.S. President Donald Trump continues to push baseless claims of voter fraud during the presidential election, which Krebs called the most secure in American history. (Photo by Greg Nash-Pool/Getty Images)