Hackers were able to remotely install surveillance software on phones and other devices using a major vulnerability in messaging app WhatsApp, it has been confirmed.
WhatsApp, which is owned by Facebook, said the attack targeted a âselect numberâ of users, and was orchestrated by âan advanced cyber actorâ.
A fix was rolled out on Friday.
On Monday, WhatsApp urged all of its 1.5 billion users to update their apps as an added precaution.
The attack was first discovered earlier this month.
WhatsApp promotes itself as a âsecureâ communications app because messages are end-to-end encrypted, meaning they should only be displayed in a legible form on the sender or recipientâs device.
However, the surveillance software would have let an attacker read the messages on the targetâs device.
âJournalists, lawyers, activists and human rights defendersâ are most likely to have been targeted, said Ahmed Zidan from the non-profit Committee to Protect Journalists.