We have been hearing about data breach of such sites for a long time now, so much so that some of us are unfazed by it.

But the latest news on a massive Facebook data leak should worry you because not only your email address is involved this time.

Affecting millions worldwide

Few days ago a user created a Telegram bot allowing users to query the database for a low fee, enabling people to find the phone numbers linked to a very large portion of Facebook accounts.This obviously has a huge impact on privacy. pic.twitter.com/lM1omndDET

— Alon Gal (Under the Breach) (@UnderTheBreach) January 14, 2021

Cybersecurity company Hudson Rock's co-founder Alon Gal tweeted about the data breach a few months ago, warning people that the data is being sold for a very low price but he updated the thread on 3 April claiming that someone has released it for free.

The database leak of 533,313,128 Facebook users worldwide also includes 11,675,894 Malaysian accounts.

Full list of affected users by country pic.twitter.com/Wrrzd0WyxE

— Alon Gal (Under the Breach) (@UnderTheBreach) January 14, 2021

Interestingly, Malaysia has some of the highest number of hacked accounts in the world.

"Details include: Phone number, Facebook ID, Full name, Location, Past Location, Birthdate, (Sometimes) Email Address, Account Creation Date, Relationship Status, Bio.

"Bad actors will certainly use the information for social engineering, scamming, hacking and marketing," Gal Tweeted.

How to check if your data has been leaked?

Following Gal's Tweets, Microsoft Regional Director and creater of "Have I Been Pwned" website has spoken about how you can use the site to check if your email address has been in a data breach, including the Facebook one.

On first review, it's an extensive data set with one file per country and a header row as follows:phone,uid,email,first_name,last_name,gender,date_registered,birthday,location,hometown,relationship_status,education_last_year,work,groups,pages,last_update,creation_time

— Troy Hunt (@troyhunt) April 3, 2021

However, Hunt has said that email breach, in this case, was very scarce. The number is only at about 2.5 million, which is only about 0.5 per cent of the more than half a billion account information leaked.

Phone numbers and other details were more readily available.

But for spam based on using phone number alone, it's gold. Not just SMS, there are heaps of services that just require a phone number these days and now there's hundreds of millions of them conveniently categorised by country with nice mail merge fields like name and gender.

— Troy Hunt (@troyhunt) April 3, 2021

Considering that a lot of verifications, including from banks use phone numbers, it is quite scary to know that our numbers are available to any Tom, Dick and Harry.