Companies Struggle to Sort How to Comply With SEC Cyber Rules

Some public companies are still trying to figure out how to comply with new rules from the US Securities and Exchange Commission requiring speedy disclosure of significant cyberattacks.

Those rules, which kicked in Monday, require companies to report cyber incidents within four business days of determining they are “material” to shareholders. The SEC previously required firms to disclose major events that would be of shareholder interest, but didn’t specify cyber events.

Making that determination isn’t so easy, said Erez Liebermann, partner at Debevoise & Plimpton law firm.

In the past three months, Liebermann has advised more than 50 publicly ...