Sony confirmed that some employees had received "an email claiming to be from the G.O.P.," adding that it was "working with law enforcement." The F.B.I. was also aware of the email.
The set of Sony documents released by hackers include salary information, employee Social Security numbers and marketing presentations.
Sony and the F.B.I. have not yet identified the hackers, although there has been great discussion online that North Korea was involved, while another theory involves a former Sony employee.