Feds warn of rising threats against health care sector, doctors among assassination targets The U.S. Department of Homeland Security said threats and violence against the healthcare sector, including hospitals and doctors, are rising sharply. A cyberextortion group believed to be based in Russia has claimed responsibility for the cyberattack in underground or dark web forum posts. The alert comes after a major cyberattack on Lurie Children's Hospital on Jan. 31 took offline the hospital's main computer network