A cybersecurity firm has reported it's uncovered the theft of credentials from some 360 million accounts and the details are available for sale on cyber black markets.
The discovery could represent more of a risk to consumers and companies than stolen credit card data because of the chance the sets of user names and passwords could open the door to online bank accounts, corporate networks, health records and virtually any other type of computer system.
Alex Holden, chief information security officer of Hold Security LLC, said in an interview that his firm obtained the data over the past three weeks, meaning an unprecedented amount of stolen credentials was available for sale underground.
"The sheer volume is overwhelming," said Holden, whose firm last year helped uncover a major data breach at Adobe Systems Inc in which tens of millions of records were stolen.
Holden said he believed the 360 million records were obtained in separate attacks, including one that yielded some 105 million records, which would make it the largest single credential breaches known to date.
He said he believed the credentials were stolen in breaches that have yet to be publicly reported. The companies attacked may remain unaware until they were notified by third parties who find evidence of the hacking, he said.
"We have staff working around the clock to identify the victims," he said.
He has not provided any information about the attacks to other cybersecurity firms or authorities, but intended to alert the companies involved if his staff could identify them.
The massive trove of credentials included user names, which were typically email addresses, and passwords that in most cases were in unencrypted text.
Holden said that in contrast, the Adobe breach, which he uncovered in October 2013, yielded tens of millions of records that had encrypted passwords, which made it more difficult for hackers to use them.
The email addresses were from major providers such as AOL, Google, Microsoft and Yahoo and almost all Fortune 500 companies and nonprofit organisations. Holden said he alerted one major email provider that was a client, but he declined to identify the company, citing a nondisclosure agreement.
Heather Bearfield, who ran the cybersecurity practice for accounting firm Marcum LLP, said she had no information about the information that Hold Security uncovered, but that it was plausible for hackers to obtain such a large amount of data because these breaches were on the rise.
She said hackers could do far more harm with stolen credentials than with stolen payment cards, particularly when people used the same login and password for multiple accounts.
"They can get access to your actual bank account. That is huge," Bearfield said.
"That is not necessarily recoverable funds."
Wade Baker, a data breach investigator with Verizon Communications, said that the number of attacks targeting payment cards through point-of-sales systems peaked in 2011. That was partly because banks and retailers have gotten better at identifying that type of breach and quickly moved to prevent crooks from making fraudulent transactions, he said.
In addition to the 360 million credentials, the criminals were selling some 1.25 billion email addresses, which would be of interest to spammers, Hold Security said in a statement on its website.