The relentless days-long cyberattack on GitHub showed that someone was willing to use hundreds of thousands of innocent internet users to try to take down two single pages set up by an organization fighting Chinese censorship.

A group of cybersleuths has discovered that someone is indeed China, as everyone suspected. More importantly, they've also learned that the attack was carried out with a powerful new cyberweapon, whose existence was previously unknown.

Researchers at the ?Citizen Lab—a digital watchdog at the University of Toronto's Munk School of Global Affairs—are calling it the "Great Cannon." It's a tool essentially capable of monitoring internet traffic and targeting anyone its operators decide to hit, sending back malware or spyware, or using the target to flood another site with traffic.

"The operational deployment of the Great Cannon," read a Citizen Lab ?report, published on Friday, "represents a significant escalation in state-level information control: the normalization of widespread and public use of an attack tool to enforce censorship."

The Great Cannon was used to hijack and redirect the internet traffic to flood two GitHub pages, in an unprecedented distributed denial of service, or DDoS, attack. The influx of traffic overwhelmed the site's servers, turning hundreds of thousands of users into unbeknownst conduits and taking down two pages hosted on GitHub by GreatFire, a group that monitors Chinese censorship and uses the site to circumvent it.

The Great Cannon can be used to hack practically anyone who visits a non-encrypted website or ad hosted in China.

The Great Cannon is capable of hijacking connections going through China's internet infrastructure for the purpose of mounting this kind of DDoS attacks in the service of censorship. But in theory, it could just as easily be used to hack practically anyone who visits a non-encrypted website hosted in China, or even a website hosted elsewhere that's containing an ad hosted in China, according to the report.