Number of UK Whatsapp users targeted in ‘terrifying’ security breach still unknown

This is definitely part of mainstream political debate in the UK. this article is from a newspaper distributed to commuters. As a user of WhatsApp (and Signal, Telegram…) the end to end encryption design is what appeals to me. I just want to know what IoC’s to look for…:

[…] Whatsapp users were told to update their messaging app immediately after the company discovered a vulnerability that allowed hackers to install a malicious code on iPhones and Android phone. It was transferred by calling the target but users didn’t even have to answer their phone for it to be installed and the call log often disappeared, reported the Financial Times.

The likelihood of there being UK victims of the attack is currently being investigated by the National Cyber Security Centre (NCSC), said Digital Minister Margot James. But she added there is not yet any information about how many it could’ve been. […]

Original article here