500 million WhatsApp users' phone numbers for sale online - allegedly

And 11 million are from the UK

Around 500 million people's WhatsApp data has been leaked and is up for sale online, in what could be one of the most serious modern data breaches.

An actor who claims to be selling a database created in 2022, containing 487 million WhatsApp users' mobile numbers, posted an advert on a hacking group site.

Of those, 32 million records are from the USA and 11 million from the UK, according to the individual.

Egypt (45 million), Italy (35 million), Saudi Arabia (29 million), France (20 million), Turkey (20 million) and Russia (10 million) are among the other countries impacted by the alleged leak.

WhatsApp has more than 2 billion active users worldwide.

The person who posted the advert told Cybernews they would charge $7,000 for the US dataset, $2,500 for the UK dataset, and $2,000 for the German dataset. The seller also provided Cybernews a sample of 1,097 UK-based mobile numbers and 817 US numbers as evidence. After looking into the numbers, the publication was able to confirm they were all from WhatsApp accounts.

The seller did not elaborate on how they obtained the information in the first place, claimed they "used their strategy" to collect the data.

One possible way to obtain data like this at scale is through scraping; several applications exist to do so, but both the process of scraping and uploading the numbers to the internet is against WhatsApp's Terms of Use.

WhatsApp users should now exercise caution, as hackers often utilise phone numbers data for smishing and vishing attacks, using voicemail, email or text messages to get victims to click on a fraudulent link.

Cybersecurity experts advise users to be wary of any calls from unknown numbers and text messages (both SMS and WhatsApp). Users risk losing money or important personal information by clicking on or responding to any such voice or text-based messages.

A Meta spokesperson described the Cybernews report as purely speculative, adding that it was based on "unsubstantiated screenshots".

The spokesperson said the firm had not found any proof of a data breach on WhatsApp servers, adding that there are several methods to create a list of phone numbers.