In the wake of megabreaches at some of the Internet’s most-recognized destinations, don’t be surprised if you receive password reset requests from numerous companies that didn’t experience a breach: Some big name companies — including Facebook and Netflix — are in the habit of combing through huge data leak troves for credentials that match those of their customers and then forcing a password reset for those users.
Netflix.com, for example, sent out a notification late last week to users who made the mistake of re-using their Netflix password at Linkedin, Tumblr or MySpace. All of three of those breaches are years old, but the scope of the intrusions (more than a half billion usernames and passwords leaked in total) only became apparent recently when the credentials were posted online at various sites and services.
“We believe your Netflix account credentials may have been included in a recent release of email addresses and passwords from an older breach at another company,” the message from Neflix reads. “Just to be safe, we’ve reset your password as a precautionary measure.”
The missive goes on to urge recipients to visit Netflix.com and click the “forgot your email or password” link to reset their passwords.
Netflix is taking this step because it knows from experience that cybercriminals will be using the credentials leaked from Tumblr, MySpace and LinkedIn to see if they work on a variety of third-party sites (including Netflix).
As I wrote last year in the aftermath of the AshleyMadison breach that exposed tens of millions of user credentials, Netflix’s forensics team has been using a tool that the company released in 2014 called Scumblr, which scours high-profile sites for specific terms and data.