Cybercrime reporter Brian Krebs attributes it to a major DNS problem. Krebs explains the DNS records that tell systems how to find Facebook and Instagram “got withdrawn this morning from the global routing cables.” However, it’s unclear how this happened.
Krebs writes in a blog post:
Facebook and its sister properties Instagram and WhatsApp are suffering from ongoing, global outages. We don’t yet know why this happened, but the how is clear: Earlier this morning, something inside Facebook caused the company to revoke key digital records that tell computers and other Internet-enabled devices how to find these destinations online.
In simpler terms, sometime this morning Facebook took away the map telling the world’s computers how to find its various online properties. As a result, when one types Facebook.com into a web browser, the browser has no idea where to find Facebook.com, and so returns an error page.
Meanwhile, the New York Times reports that even Facebook isn’t entirely sure what the root cause of this issue is:
Several hours into the incident, Facebook’s security experts were still trying to identify the root issue, according to an internal memo and employees briefed on the matter. Two members of its security team, who spoke on the condition of anonymity because they were not authorized to speak publicly, said it was unlikely that a cyberattack had taken place because one hack was unlikely to affect so many apps at once.
In a statement, WhatsApp acknowledges that its service is down:
We know that some people are experiencing issues with WhatsApp at the moment. We’re working to get things back to normal and will send an update here as soon as possible.
Facebook’s Sandy Stone:
We know that some people are having trouble accessing our apps and products. We’re working to get things back to normal as quickly as possible, and we apologize for any inconvenience.