News of the breaches follows closely behind hacks targeting the Democratic National Committee, the Democratic Congressional Campaign Committee, and data leaked from the National Security Agency.
Unnamed American officials have gone to the media and blamed the first two incidents on Russian hackers, but no U.S. official has gone on the record to lay blame on any group yet. The source of the third attack remains an open question.
The FBI and other U.S. agencies are said to be investigating the media hacks, CNN reports.
Reporters are in regular contact with government officials of all types and importance, making them valuable hacking targets who work with information that can be top secret or otherwise important.