Cyber attack could spark lawsuits but not against Microsoft

A bench frames a sign outside the Microsoft office in Cambridge, Massachusetts, U.S. May 15, 2017. REUTERS/Brian Snyder

(Reuters) - Businesses that failed to update Microsoft Windows-based computer systems that were hit by a massive cyber attack over the weekend could be sued over their lax cyber security, but Microsoft Corp itself enjoys strong protection from lawsuits, legal experts said.

The WannaCry worm has affected more than 200,000 Windows computers around the world since Friday, disrupting car factories, global shipper FedEx Corp and Britain's National Health Service, among others. The hacking tool spreads silently between computers, shutting them down by encrypting data and then demanding a ransom of $300 to unlock them.