China launched a massive DDoS attack on GitHub, a source code hosting website used by programmers to collaborate on software development. The Great Cannon is a special cyber attack tool essentially capable of hijacking Internet traffic at the national level and then direct that traffic at targeted networks the attackers want to knock offline, sending back spyware or malware, or using the target to flood another website with traffic. This powerful cyber weapon seems to leverage an analytic script, which is commonly distributed by the Chinese search engine Baidu. It could also be used to intercept unencrypted man-in-the-middle (MITMMM) emails.
Source: https://thehackernews.com/2015/04/great-cannon-ddos-attack.html