WhatsApp has urged all of its 1.5 billion users to update their apps as an added precaution amidst hackers hacking into the system.
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 “select number” of users, and was orchestrated by “an advanced cyber actor”.
The attack was developed by Israeli security firm NSO Group, according to a report in the Financial Times.
The attack was first discovered earlier this month.
It involved attackers using WhatsApp’s voice calling function to ring a target’s device.
Even if the call was not picked up, the surveillance software would be installed, and, the FT reported, the call would often disappear from the device’s call log.
WhatsApp told the BBC its security team was the first to identify the flaw, and shared that information with human rights groups, selected security vendors and the US Department of Justice earlier this month.
The attack has all the hallmarks of a private company reportedly that works with governments to deliver spyware that takes over the functions of mobile phone operating systems.
WhatsApp said it was too early to know how many users had been affected by the vulnerability, although it added that suspected attacks were highly-targeted.
According to Facebook’s latest figures, WhatsApp has around 1.5bn users worldwide.
Amnesty International, which said it had been targeted by tools created by the NSO Group in the past, said this attack was one human rights groups had long feared was possible.
“They’re able to infect your phone without you actually taking an action,” said Danna Ingleton, deputy programme director for Amnesty Tech.
She said there was mounting evidence that the tools were being used by regimes to keep prominent activists and journalists under surveillance.
“There needs to be some accountability for this, it can’t just continue to be a wild west, secretive industry.”
On Tuesday, a Tel Aviv court will hear a petition led by Amnesty International that calls for Israel’s Ministry of Defence to revoke the NSO Group’s licence to export its products.