Security researchers have warned that the Chinese government has enhanced its 'Great Firewall' powers with a precisely targeted downtime tool called the Great Cannon.
A report on the Great Cannon by researchers at the University of Toronto said that it is linked to the Chinese government firewall and can be used to disrupt websites and services.
The report has tracked the tool to recent attacks on GitHub, Greatfire.org and The New York Times.
"While the attack infrastructure is co-located with the Great Firewall, the attack was carried out by a separate offensive system, with different capabilities and design, that we term the ‘Great Cannon'," said the report.
"The Great Cannon is not simply an extension of the Great Firewall, but a distinct attack tool that hijacks traffic to, or presumably from, individual IP addresses, and can arbitrarily replace unencrypted content as a man-in-the-middle.
"The operational deployment of the Great Cannon represents a significant escalation in state-level information control: the normalisation of widespread use of an attack tool to enforce censorship by weaponising users."
China is often cited as the biggest online threat to computer systems in terms of government-sanctioned hacks, but the Canadian researchers suggested that the cannon is closer to a US creation called Quantum employed by the National Security Agency (NSA).
"While employed for a highly visible attack in this case, the Great Cannon clearly has the capability for use in a manner similar to the NSA's Quantum system, affording China the opportunity to deliver exploits targeting any foreign computer that communicates with any China-based website not fully utilising HTTPS."
The researchers are certain that Chinese agents were behind the cannon attacks, and that they were so well backed that they can only have come with official government approval.
They also suggested that the assaults were a show of strength by the Chinese government.
As venerable security commentator Bruce Schneier said: "It's kind of hard for the US to complain about this kind of thing, since we do it too."
This week the US government banned Intel from providing chips to the Chinese for a supercomputer amid fears it would be used for nuclear research.
Intel wants to get inside your car, despite missing out on mobile
'We'll keep fighting to fight to keep the web free and open,' claim EFF
Breached in March by the same attackers, claim 'insiders'
And all for less than £150, according to Keith