Some experts have put the cost at up to $100 million (66 million pounds), which could include computer repair or replacement, steps to prevent a future attack and lost productivity while operations were disrupted.
The attack targeting the entertainment arm of Sony is nevertheless believed to be the most destructive ever on a private company on U.S. soil, wiping out massive amounts of data and leading to the online distribution of email, sensitive employee data and pirated copies of new movies.
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"It was as though somebody came into your house and robbed it and then burned the house down to ground," Lynton said. "As one of the investigators said to me, whoever wrote this software was very, very angry."
The Federal Bureau of Investigation determined that the North Korean government was behind the attack, launched by hackers as the studio prepared to release its bawdy comedy "The Interview," depicting the assassination of leader Kim Jong-Un. North Korea had called the film an "act of war."
Lynton said that despite the difficulties of working without a network, Sony has not missed any movie or television production deadlines, since many productions run fairly independently of the studio. Pulling together the company's financial statements is difficult, he said, but will be done in time.
The studio's 6,000 employees are scheduled to have their email system restored next week, while the computer network may take another three to six weeks, Lynton said.