LinkedIn was hit by a breach in June 2012, affecting 6 million users, the social network originally said. Nearly four years later, a clearer picture of the incident has emerged: 100 million LinkedIn users' passwords were potentially stolen.
"On May 17, 2016, we became aware that data stolen from LinkedIn in 2012 was being made available online. This was not a new security breach or hack," states an email distributed to LinkedIn users from the social network's legal team. "We took immediate steps to invalidate the passwords of all LinkedIn accounts that we believed might be at risk."
Despite these steps, LinkedIn users may still be at risk. Hackers are reportedly selling the trove of stolen emails and passwords, and even if they no longer work with LinkedIn, the credentials can potentially be used to unlock other popular sites and online services due to password reuse.
Microsoft accounts, those used to log into OneDrive, Xbox Live, Outlook.com and a host of other online services from the software giant, are already being immunized against password attacks that stem from breaches like the one suffered by LinkedIn, said Alex Weinert, group program manager of Microsoft Azure Active Directory (AD) Identity Protection.
"When it comes to big breach lists, cybercriminals and the Azure AD Identity Protection team have something in common—we both analyze the passwords that are being used most commonly," he wrote in a blog post. "Bad guys use this data to inform their attacks—whether building a rainbow table or trying to brute force accounts by trying popular passwords against them. What *we* do with the data is prevent you from having a password anywhere near the current attack list, so those attacks won't work."
Microsoft then uses the data it collects to outright block users from choosing a commonly used password or one that is similar. This precaution is already active on Microsoft user accounts and is currently in private beta for enterprise customers in Azure AD. In the coming months, Microsoft plans to enable the feature across all of its 10 million-plus Azure AD tenants, added Weinert.
While it's a seemingly consumer-friendly step to take, James Romer, chief security architect at SecureAuth, said that the move by Microsoft hints at an overreliance on username-password combinations for keeping its user data out of the hands of hackers.
"Microsoft reacting like this is the easiest way for them to at least mitigate the risk caused by this password reuse. It buys them some time and reduces embarrassment should they also be breached," he wrote in an email sent to eWEEK. "It is an admission that a problem exists within their environment where usernames and passwords are the sole protection points."
Passwords fall short in preventing modern-day cyber-attacks, argued Romer. "Relying on passwords in today's complex landscape is not solving a problem or preventing the inevitable. The point of attack still remains the same and therefore the underlying vulnerability remains."