It is believed a WhatsApp hack may have been targeting journalists and government critics in the Middle East.
Anyone who uses the app is urged to update it after it emerged that hackers had used the voice chat feature to inject spyware onto devices.
According to the Financial Times an Israeli security company developed the attack.
So how did this actually work? John Kennedy from Silicon Republic explains:
"All the attackers had to do was simply ring [a person's] number on WhatsApp and whether they answered it or not it installed spyware which then was able to take control of the phone's camera and microphone for whoever these interests are, so basically record all the data they need. The scary thing of this is that it basically could have been used to individually target people whose lives could be in danger if their information was compromised."
Cover image via @whatsapp/Instagram