Facebook users can now use phone numbers to check on the Have I Been Pwned site whether their numbers and details have been leaked in the social networking platform's recent data breach.
Learn more: Facebook: Millions of users' data leaked - How to see if your data was exposed
Last weekend, a cybercriminal leaked data from 533 million Facebook users. This data includes phone numbers and Facebook IDs for almost all of the exposed accounts. Other information may have also been leaked, such as member name, gender, relationship status, location, occupation, date of birth, and email address.
See also: Ireland's Data Protection Commission (DPC) investigates Facebook data leak
According to reports, this data was initially collected in 2019 and sold privately at that time. Slowly, the data began to be sold between different hacking groups at increasingly lower prices, until it was released for free on a hacking forum this weekend.
Almost immediately the data was added to the data breach notification service Have I Been Pwned, so that users could see if their email had been leaked via the Facebook data leak.
The problem is that in this leak there are mainly phone numbers and fewer emails.
See also: Mark Zuckerberg's phone number leaked online
According to Troy Hunt, creator of Have I Been Pwned, over 500 million phone numbers have been leaked, but only a few million emails. Therefore, >99% of users who check on the site if their data has been leaked will not necessarily get a correct answer (since they only check with email).
To more accurately notify users, Hunt has updated Have I Been Pwned so that users can now search their phone numbers on the site to determine if the leak exposed their Facebook information.
When searching by phone number, users must include their country code.
For example, a user from New York should search by prefixing the country code 1, followed by their full number (e.g. search in the format “19175555555”).
Someone in the UK would also need to include the country code. So the search would look something like this: “+442071838750”.
Hunt states that the + symbol is optional and will be removed during the search.
The ability to search Have I Be Pwned by phone number is very helpful because Facebook users will be able to see more accurately whether their data has been leaked.
All Facebook users should be very careful, as the leaked data can be used by various criminals to carry out attacks (phishing, smishing, etc.).
Source: Bleeping Computer
