Renowned security researcher Troy Hunt reported a massive leak consisting of 773 million unique email IDs and 21 million unique passwords, which he refers to as "Collection #1".
Hunt said that some people have reached out to him and pointed him to a collection on MEGA that has 12,000 files with a total size of 87GB, and nearly 2.7 billion records.
Hunt said that the files have been removed from the hosting platform, but they persist on hacking forums.
He said that the forum post described the source of the data as "a collection of 2000+ dehashed databases and Combos (combinations of email addresses and passwords) stored by topic."
Troy Hunt said that:
(I found a combination of different delimiter types including colons, semicolons, spaces and indeed a combination of different file types such as delimited text files, files containing SQL statements and other compressed archives.)"
On his page, Hunt described this leak as "a set of email addresses and passwords totalling 2,692,818,238 rows," with "1,160,253,228 unique combinations of email addresses and passwords," "unique email addresses totalled 772,904,991," with "21,222,975 unique passwords."
This is one of the biggest data leak since Yahoo!'s massive data leak in 2013 that affected nearly 3 billion accounts.
"However, what I can say is that my own personal data is in there and it's accurate; right email address and a password I used many years ago," Hunt said.