Git repository hosting service GitHub Inc., has been under a massive distributed denial of service (DDoS) since Thursday with China named as the culprit.

GitHub said in a blog post that the DDoS attack was the largest in their history and explained that it involves a wide combination of attack vectors. The vectors include methods that have been seen previously, as well as what GitHub calls “some sophisticated new techniques” which they describe as using the web browsers of unsuspecting, uninvolved people to flood the site with traffic.

The new method is said to include redirecting traffic meant for China’s most popular search engine to GitHub. Given the hundreds of millions of internet users in China, could feasibly, if the hack or method is widespread, be delivering a staggering amount of traffic to the site.

The attack is believed to be related to GitHub hosting code for tools that can be used to bypass censorship in countries such as China, although GitHub has not confirmed that other than to say “we believe the intent of this attack is to convince us to remove a specific class of content.” According to The Wall Street Journal, the traffic has been targeted at the pages of two such projects that specifically target bypassing the Great Firewall of China.

In posts to Twitter over the weekend, GitHub described their various attempts to mitigate the attack, including noting at one stage that those behind the attack were changing tactics.

The ongoing DDoS attack has changed tactics. We are experiencing intermittent service outages and working to mitigate.

— GitHub Status (@githubstatus) March 29, 2015

By Sunday evening, it would appear that GitHub has gotten on top of the attacks, at least at the time writing, with a new tweet reading

All systems reporting at 100%. Attack traffic continues, so we remain on high alert.

— GitHub Status (@githubstatus) March 30, 2015

GitHub users should probably expect intermittent disruptions though going forward particularly in the methods of the attack continue to change.