Sony Pictures Entertainment has hired Boies, Schiller & Flexner to clamp down on media companies that have republished confidential—and at times embarrassing—information leaked about the company through a hacker. But its efforts may be in vain.

The cyberattack on the Japanese entertainment company by a group that calls itself the Guardians of Peace has uncovered information about Sony’s employee salaries, health records, movie stars’ fees and internal email exchanges.