That massive reported 'data breach' was just hype, Mail.ru says

Hold suggested that nearly 57 million of the stolen email accounts uncovered were from the popular Russian service Mail.ru. But more than 99.9 percent of the Mail.ru account credentials in a sample examined by the provider are invalid, the Russian company said.

Gmail, Hotmail, and Yahoo accounts were also included in the stash Hold claimed to have recovered, as were credentials from numerous other services.

"The database is most likely a compilation of a few old data dumps collected by hacking Web services where people used their email address to register," Mail.ru said. "Therefore, it is fair to assume that the sole purpose of issuing the report was to create media hype and draw the public attention to Holden’s cybersecurity business."

Hold Security's chief information security officer is Alex Holden. 

Even if many of the accounts included in the data set are inactive, there could still be a risk for users who rely on their email address as a user ID for other services, Holden said by email.

In addition, the credentials could be used for spam or phishing, thereby exposing "a sizable portion of the user base to unwanted abuse," he added.

It wasn't until a request from Reuters that Mail.ru learned of Hold's report, the Russian provider said by email. The company then contacted Hold and received a sample of the data. It did not specify the size of the sample it obtained, but an initial analysis indicated that no live accounts were included, Mail.ru said early Thursday.

Since then, further analysis by Mail.ru found that 22.6 percent of the database entries analyzed contain email addresses that do not exist while 64.3 percent contain incorrect passwords or no passwords at all. A full 12.4 percent of the remaining accounts had already been marked as suspicious and blocked by Mail.ru, the company said, meaning that its system considers them either hacked or controlled by a robot.

"Those accounts cannot be accessed by simply entering username and password, as the owner would have to recover access to the account first," the provider explained.

In its original announcement, Hold itself noted that a sizable portion of the credentials it found in the stash of 272 million were duplicates of credentials it had already found in other data sets.

The bottom line is that only 0.018 percent of the username/password combinations in the sample analyzed might have worked, and Mail.ru has already notified the affected users. A fuller account of Mail.ru's analysis is available in its blog post on the topic.

"The confirmations that we’re now seeing from Mail.ru confirm what was obvious from the outset -- the data is fake," said Troy Hunt, a security expert and creator of the site Have I Been Pwned, in an email.

Data breaches are often fabricated, Hunt explained, frequently by someone who hopes either to sell the data or to build a reputation based on having allegedly stolen it.

"Proper verification of these incidents is absolutely paramount, or we get what we’ve had in the press the last few days: accusations of email providers being hacked and calls for people to change passwords when there was now clearly never a risk in the first place," said Hunt, who also wrote a blog post on the topic.

Google and Yahoo did not immediately respond to requests for comment. Microsoft declined to comment.