WASHINGTON — Investigators say a crippling cyberattack against Sony Pictures Entertainment likely is the work of North Korea, in what would be the first known case of the reclusive nation using its growing hacking capability to cause major disruptions to a company in the United States.

The attack brought Sony, one of Hollywood’s biggest studios, to a near-standstill last week, forcing employees to use paper and pens instead of their computers. Hackers also deleted files from hard drives, uploaded several unreleased films to the Internet and leaked sensitive personal information about thousands of Sony employees.

The cyberattack may have come in retaliation for Sony’s upcoming release, the “Interview,” a comedy built around a fictional CIA plot to kill North Korea’s supreme leader, Kim Jong Un, said people familiar with the probe who spoke on the condition of anonymity because the investigation is ongoing.

North Korean officials have repeatedly complained about the movie – due to open in theaters on Christmas – warning of “stern” and “merciless” retaliation. On Tuesday a North Korean government spokesman declined to comment on whether it was behind the Sony incident, according to a report by BBC News, which quoted the spokesman as saying, “Wait and see.”

If investigators’ beliefs turn out to be true, the hack on Sony would mark a troubling new development at the intersection of international relations, commerce and cyberspace.

“This is a step beyond what they’ve done in the past, but it’s a logical trajectory for them,” said James Lewis, a cybersecurity expert at the Center for Strategic and International Studies. He said he did not have definitive knowledge that North Korea was responsible for the Sony hack but noted that it shared characteristics of hacks by the North against South Korean firms.