Hackers have managed to install a software which monitors cellular phones and other gadgets when using WhatsApp.
This app, which is Facebook property, stated that it was the target of an attack on a selective number of users and orchestrated by someone who is conversant with the technology.
The issue was solved on Friday with WhatsApp calling on its 1.5 billion users yesterday to update the app as a precaution.
The Financial Times reported that the attack was developed by an Israeli security firm, NSO Group. WhatsApp was aware of the attack in the beginning of May.
This app promotes itself as one of the most safe means of communication as encrypted messages are visible only between the sender and the receiver, and the content is supposed to remain secret between them.
However, the created software enabled the hacker to read the messages of his targets. It is believed that journalists, lawyers and human rights activists were among those targeted in the attack.