Thousands of employees at Stryker woke up on Wednesday to find their cellphones and laptops were suddenly disabled by a major cyberattack against the medical devices company.

Add Yahoo as a preferred source to see more of our stories on Google. A major cyberattack has crippled the global networks of Stryker, one of the world's largest medical device companies, with an Iran-linked hacking group claiming responsibility and warning it marks "the beginning of a new chapter in cyber warfare".