WhatsApp’s newly unsealed court documents have exposed the extensive reach of NSO Group’s Pegasus spyware operation, which targeted “between hundreds and tens of thousands” of devices, according to testimony from the company’s head of research and development. The Israeli surveillance firm charged government customers up to $6.8 million for one-year licenses, generating at least $31 million in revenue in 2019 alone, TechCrunch first reported.

The documents detail previously unknown hacking tools named “Hummingbird,” “Eden,” and “Heaven,” developed specifically to compromise WhatsApp users’ devices. The revelations emerge from WhatsApp’s ongoing 2019 lawsuit against NSO Group for alleged violations of U.S. anti-hacking laws.

Further reading: NSO, Not Government Clients, Operates Its Spyware.