The Facebook owned WhatsApp, which has 1.5 billion users, announced that it has been made aware of the hack which has infected an unknown number of devices with the malware.

BusinessInsider.com reported about a vulnerability that allowed hackers to install surveillance technology through WhatsApp, which gave them access to information including location data and private messages. Even if the target didn't pick up, the malware was able to infect the phone.

There has been several sources that have pointed to the Israeli firm NSO Group as being behind the spyware. However, NSO has neither directly confirmed or denied involvement.

Facebook says it has provided information to law enforcement and has now fixed the vulnerability but it's still encouraging all users to update to the latest version.