Breach-Fueled Credential Stuffing, the “Philly Special” and Lessons in Defense

by Chris Ryan 4 min read March 28, 2019

Be warned. I’m a Philadelphia sports fan, and even after 13 months, I still relish in the only Super Bowl victory I’ve ever known as a fan. Having spent more than two decades in fraud prevention, I find that Super Bowl LII is coalescing in my mind with fraud prevention and lessons in defense more and more.

Let me explain:

It’s fourth-down-and-goal from the one-yard line. With less than a minute on the clock in the first half, the Eagles lead, 15 to 12. The easy option is to kick the field goal, take the three points and come back with a six-point advantage. Instead of sending out the kicking squad, the Eagles offense stays on the field to go for a touchdown. Broadcaster Cris Collingsworth memorably says, “Are they really going to go for this? You have to take the three!”

On the other side are the New England Patriots, winners of two of the last three Super Bowls. Love them or hate them, the Patriots under coach Bill Belichick are more likely than any team in league history to prevent the Eagles from scoring at this moment.

After the offense sets up, quarterback Nick Foles walks away from his position in the backfield to shout instructions to his offensive line. The Patriots are licking their chops. The play starts, and the ball is snapped — not to Foles as everyone expects, but to running back Corey Clement. Clement takes two steps to his left and tosses the ball the tight end Trey Burton, who’s running in the opposite direction. Meanwhile, Foles pauses as if he’s not part of the play, then trots lazily toward the end zone. Burton lobs a pass over pursuing defenders into Foles’ outstretched hands. This is the “Philly Special” — touchdown!

Let me break this down: A third-string rookie running back takes the snap, makes a perfect toss — on the run — to an undrafted tight end. The tight end, who hasn’t thrown a pass in a game since college, then throws a touchdown pass to a backup quarterback who hasn’t caught a ball in any athletic event since he played basketball in high school. A play that has never been run by the Eagles, led by a coach who was criticized as the worst in pro football just a year before, is perfectly executed under the biggest spotlight against the most dominant team in NFL history.

So what does this have to do with fraud?

There’s currently an outbreak of breach-fueled credential stuffing. In the past couple of months, billions of usernames and passwords stolen in various high-profile data breaches have been compiled and made available to criminals in data sets described as “Collections 1 through 5.” Criminals acquire credentials in large numbers and attack websites by attempting to login with each set — effectively “stuffing” the server with login requests. Based on consumer propensity to reuse login credentials, the criminals succeed and get access to a customer account between 1 in 1,000 and 1 in 50 attempts. Using readily available tools, basic information like IP address and browser version are easy enough to alter/conceal making the attack harder to detect.

Credential stuffing is like the Philly Special:

  • Credential stuffing doesn’t require a group of elite all-stars. Like the Eagles’ players with relatively little experience executing their roles in the Philly Special, criminals with some computer skills, some initiative and the guts to try credential stuffing can score.
  • The best-prepared defense isn’t always enough. The Patriots surely did their homework. They set up their defense to stop what they expected the Eagles to do based on extensive research. They knew the threats posed by every Eagle on the field. They knew what the Eagles’ coaches had done in similar circumstances throughout their careers. The defense wasn’t guessing. They were as prepared as they could have been.

It’s the second point that worries me when I think of credential stuffing.

Consumers reuse online credentials with alarming frequency, so a stolen set of credentials is likely to work across multiple organizations, possibly even yours. On top of that, traditional device recognition like cookies can’t identify and stop today’s sophisticated fraudsters.

The best-prepared organizations feel great about their ability to stop the threats they’re aware of. Once they’ve seen a scheme, they make investments, improve their defenses, and position their players to recognize a risk and stop it. Sometimes past expertise won’t stop the play you can’t see coming.

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