Major security breaches found in Google, Yahoo e-mail services

Hundreds of millions of hacked usernames and passwords for email accounts and other websites are being traded in Russia’s criminal underworld, Reuters reports, citing a security expert.

The discovery of 272.3 million stolen accounts included a majority of users ofMail.ru <MAILRq.L>, Russia’s most popular email service, and smaller fractions of Google <GOOGL.O>, Yahoo <YHOO.O> and Microsoft <MSFT.O> email users, said Alex Holden, founder and chief information security officer of Hold Security.

It is one of the biggest stashes of stolen credentials to be uncovered since cyber attacks hit major US banks and retailers two years ago.

Holden was previously instrumental in uncovering some of the world’s biggest known data breaches, affecting tens of millions of users at Adobe Systems <ADBE.O>, JPMorgan <JPM.N> and Target <TGT.N> and exposing them to subsequent cyber crimes.

The latest discovery came after Hold Security researchers found a young Russian hacker bragging in an online forum that he had collected and was ready to give away a far larger number of stolen credentials that ended up totaling 1.17 billion records.

After eliminating duplicates, Holden said, the cache contained nearly 57 millionMail.ru accounts - a big chunk of the 64 million monthly active email users Mail.rusaid it had at the end of last year. It also included tens of millions of credentials for the world’s three big email providers, Gmail, Microsoft and Yahoo, plus hundreds of thousands of accounts at German and Chinese email providers.

“This information is potent. It is floating around in the underground and this person has shown he’s willing to give the data away to people who are nice to him,” said Holden, the former chief security officer at US brokerage R.W. Baird. “These credentials can be abused multiple times,” he said.