ATLANTA - Companies across the globe are on high alert to tighten up network security to avoid being the next company brought to its knees by hackers like those that executed the dramatic cyberattack against Sony Pictures Entertainment.

The hack, which a U.S. official has said investigators believe is linked to North Korea, culminated in the cancellation of a Sony film and ultimately could cost the movie studio hundreds of millions of dollars. That the hack included terrorist threats and was focused on causing major corporate damage, rather than on stealing customer information for fraud like in the breaches at Home Depot and Target, indicates a whole new frontier has emerged in cybersecurity. Suddenly every major company could be the target of cyberextortion.

"The Sony breach is a real wakeup call even after the year of megabreaches we've seen," says Lee Weiner, Boston security firm Rapid7's senior vice president of products and engineering.

This should signal to all U.S. businesses that they need to "take cybersecurity as serious as physical security of their employees or security of their physical facilities," says Cynthia Larose, chairwoman of the privacy and security practice at the law firm Mintz Levin in Boston.

The breach is particularly troubling in Hollywood, where secrecy is supposed to be paramount to ensure that movie secrets don't get leaked.

Studios are trying to tighten up procedures in the wake of the Sony attack. Warner Bros. executives earlier this week ordered a companywide password reset and sent a five-point security checklist to employees advising them to purge their computers of any unnecessary data, in an email seen by the Associated Press. "Keep only what you need for business purposes," the message said.