Phone numbers, email addresses, and personal information of over 500 million Facebook users, was published on a hacker forum, in one of the biggest FaceBook breaches to date. This was first reported last week by Business Insider.

Cybercrime research firm Hudson Rock CTO Alon Gal, told Business Insider, “the data included full names of users, Facebook IDs, locations, dates of birth, biographies, phone numbers, and email addresses. A selection of records from the cache was verified against Facebook’s password reset feature, and were found to be genuine.”

This data leak affected approximately 533 million users, in 106 countries, including 32 million in the United States.

“A database of that size containing the private information such as phone numbers of a lot of Facebook’s users would certainly lead to bad actors taking advantage of the data,” said Gal.

Facebook attributed the data leak to a temporary vulnerability that was fixed in 2019. “This is old data that was reported in 2019. We discovered and fixed this problem in 2019,” a Facebook spokesman said in a message sent in response to a TASS request. Russia had more than 10 million users affected by this breach.