Facebook has filed a lawsuit against the Israeli cyber Intelligence firm NSO Group in a US Federal Court for spreading spyware to 1,400 mobile devices in 20 countries in May.

According to the company's accusation, the attack was carried out using WhatsApp. The WhatsApp-based attackers inserted a Pegasus software into the victim's phones by simply putting a WhatsApp call through. Even if the victim didn't pick up the call, the phone was infected, once the call had gone through.

But WhatsApp comes with end-to-end encryption, right?

The spyware did not break WhatsApp's encryption but was able to access the messages after they had been decrypted on the user's device, Facebook claims.

It further stated that the hack wasn't a wide-ranging one and was instead targeted towards Saudi dissidents, Mexican journalists, Bahraini human rights activists among others.

NSO has, however, denied the accusations. It has stated that Pegasus was operated only by intelligence or law enforcement agencies and was not used to target individuals.

"In the strongest possible terms, we dispute today's allegations and will vigorously fight them. The sole purpose of NSO is to provide technology to licensed government intelligence and law enforcement agencies to help them fight terrorism and serious crime. Our technology is not designed or licensed for use against human rights activists and journalists. It has helped to save thousands of lives over recent years," NSO stated in a letter to Engadget.

It further stated that the technology has been used in counter-terror operations. It was working towards protecting people's right to life, security and bodily integrity and followed UN guidelines one business and human rights.

WhatsApp Vice-President, Will Cathcart, however, differs on the subject, "[W]e learned that the attackers used servers and Internet-hosting services that were previously associated with NSO," he wrote. "In addition, as our complaint notes, we have tied certain WhatsApp accounts used during the attacks back to NSO. While their attack was highly sophisticated, their attempts to cover their tracks were not entirely successful," he told The Washington Post.

Despite the varying narratives, the outcome of the case remains to be seen. What's confirmed is that NSO's credibility will be dented unless it gets acquitted in the case.

iPhone apps
WhatsApp and Facebook messenger icons are seen on an iPhone in Manchester , Britain March 27, 2017. REUTERS/Phil Noble