China Uses ‘Great Cannon’ to Disrupt Internet, Researchers Say

China has begun using an “offensive system” able to disrupt access to websites outside its borders, according to researchers at the University of Toronto.

The deployment of this system represents a “significant escalation in state-level information control,” the university’s Citizen Lab said in a report posted to its website Friday. This system, dubbed the “Great Cannon” by the researchers, was used in recent attacks on GitHub Inc. and servers used by, according to the report.

China’s communist government, through the Internet censorship system known as the Great Firewall, has already banned domestic access to foreign websites including Google, Facebook and Twitter. Authorities curb the flow of information they deem damaging to the government.

“The Great Cannon is not simply an extension of the Great Firewall, but a distinct attack tool,” researchers led by Bill Marczak and Nicholas Weaver said in the report.

China’s foreign ministry, defense ministry and Internet regulator have repeatedly denied that the nation is behind any cyber attacks. Hua Chunying, a foreign ministry spokesperson, told reporters on March 30 that the country is “one of the major victims” of cyber attacks.

Github, a San Francisco-based service that helps programmers and tech companies share ideas for software development, experienced last month what it called its biggest-ever distributed denial of service attack.

The Wall Street Journal, citing cybersecurity experts it didn’t identify, reported March 29 the attack may have originated in China and routed overseas users of Baidu, China’s biggest search engine, to overwhelm two GitHub pages that linked to sites banned in China.

— With assistance by Xin Zhou

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