Botnets have existed for at least a decade. As early as 2000, hackers were breaking into computers over the Internet and controlling them en masse from centralized systems. Among other things, the hackers used the combined computing power of these botnets to launch distributed denial-of-service attacks, which flood websites with traffic to take them down.
But now the problem is getting worse, thanks to a flood of cheap webcams, digital video recorders, and other gadgets in the “Internet of things.” Because these devices typically have little or no security, hackers can take them over with little effort. And that makes it easier than ever to build huge botnets that take down much more than one site at a time.
In October, a botnet made up of 100,000 compromised gadgets knocked an Internet infrastructure provider partially offline. Taking down that provider, Dyn, resulted in a cascade of effects that ultimately caused a long list of high-profile websites, including Twitter and Netflix, to temporarily disappear from the Internet. More attacks are sure to follow: the botnet that attacked Dyn was created with publicly available malware called Mirai that largely automates the process of coöpting computers.