A US district judge has ruled that the NSO Group, an Israeli spyware maker, must share its secret code with WhatsApp, allowing the company to explore the full functionality of the Pegasus spyware. The ruling is a result of a lawsuit filed by WhatsApp in 2019, alleging that Pegasus was used to spy on 1,400 WhatsApp users. The NSO Group had sought to block all discovery in the lawsuit, citing US and Israeli restrictions. The court's decision is seen as a significant milestone in WhatsApp's efforts to protect its users against unlawful attacks.