Spyware crafted by an "advanced cyber actor" infected multiple targeted mobile phones through the popular WhatsApp communications program without any user intervention through in-app voice calls, the company said. The Financial Times identified the actor as Israel's NSO Group, and a WhatsApp spokesman later said "we're certainly not refuting any of the coverage you've seen." WhatsApp says it fixed the security hole through a server-side fix on May 10, and released patched Android and iOS apps on Monday. Users are urged to update their apps.