Cybercriminals who use giant floods of data to knock sites offline are leveraging a never-before-seen method that has the potential to increase the damaging effects of those floods by an unprecedented 4 billion times, researchers warned on Tuesday.

Like many other types of distributed denial-of-service attacks, the attacks send a modest amount of junk data to a misconfigured third-party service in a way that causes the service to redirect a much larger response at the intended target. So-called DDoS amplification attacks are popular because they lower the requirements needed to overwhelm their targets. Rather than having to marshal huge amounts of bandwidth and computing power, the DDoSer locates servers on the Internet that will do it for them.

It’s all about amplification