The US company WhatsApp has filed an unprecedented complaint against an Israeli spyware company accused of helping governments in the Middle East and Mexico spy on activists and journalists.

Facebook's social media company is suing NSO, an Israeli spy company, which Wattsab says is responsible for a series of sophisticated cyber attacks that have violated US law.

The US company announced in May that it was attacked by a spy program that provides access to the content of WhatsApp correspondence on smartphones.

"After months of investigation, we can find out who launched this attack," company director Will Cathcart said in an article in a US newspaper on Tuesday.

In a statement, the company accused NSO of being targeted by secret attacks "at least 100 members of civil society, an unequivocal pattern of exploitation."

She believes the technology sold by NSO has been used to target mobile phones to more than 1,400 users in 20 different countries over a 14-day period from the end of April to mid-May.

In this short period, WhatsApp believes that those who have been subjected to cyber attacks are prominent human rights defenders, lawyers, prominent religious figures, well-known journalists, and officials of humanitarian organizations.

It also believes that a number of women previously targeted by cyber violence, individuals who have faced assassination attempts and threats of violence, as well as their relatives, are targeted.

The hackers were able to exploit a vulnerability in the application to introduce an information program to smart phones by simply contacting users of the application WhatsApp, which is currently used by 1.5 billion people in the world.

In a lawsuit filed in a California court on Tuesday, WhatsApp is demanding a permanent injunction preventing SNO from trying to access whatsapp's computer systems and its parent company's Facebook systems.

It also asked the court to rule that NSO violated US federal and California law against cyber fraud, and violated its contracts with WhatsApp and "sinful infringement" of Facebook property.