Spyware Firm Cites Security in Challenge to Facebook’s WhatsApp

Israeli spyware firm NSO Group is making a national security argument as it challenges a federal court ruling that let Facebook Inc.‘s WhatsApp sue over malware that allegedly targeted users of the messaging platform.

NSO argues the lawsuit is a bid to block foreign countries from using its technology for counterterrorism and law-enforcement investigations.

“By suing NSO for its conduct as an agent of foreign states, WhatsApp is asking U.S. courts to meddle in the sovereign affairs of those states,” lawyers for NSO said in a Monday filing in the U.S. Court of Appeals for the Ninth Circuit.

The ...