WASHINGTON — Federal investigators have now connected the hacking of Sony Pictures Entertainment Inc. to North Korea, a U.S. official said Wednesday, though it remained unclear how the federal government would respond to a break-in that exposed sensitive documents and ultimately led to terrorist threats against moviegoers.

The official, who said a more formal statement might come soon, spoke on condition of anonymity because the official was not authorized to openly discuss an ongoing criminal case. A security professional with knowledge of the breach also said investigators had strong circumstantial evidence and technical commonalities pointing to North Korea.

Until Wednesday, the Obama administration had been saying it was not immediately clear who might have been responsible for the computer break-in. North Korea has publicly denied it was involved, though it did issue a statement earlier this month describing the hack as a “righteous deed.”

The unidentified hackers had demanded that Sony cancel its release of the movie “The Interview,” a comedy that included a gruesome scene depicting the assassination of North Korea’s leader. Sony on Wednesday canceled the Dec. 25 release, citing the threats of violence at movie theaters that planned to show the movie, and later said there were no further plans to release the film.

The disclosure about North Korea’s involvement came just after Sony hired FireEye Inc.’s Mandiant forensics unit, which last year published a landmark report with evidence accusing a Chinese Army organization, Unit 61398, of hacking into more than 140 companies over the years.