For a few days now, coding hub GitHub has been flooded by an enormous amount of traffic coming from a cyber attack, allegedly stemming from China, which has caused intermittent outages on the service.

This kind of hacker attack is known as DDoS attack, one of the most common on the worldwide web. According to media reports, the flood of Internet traffic to the website originated from Chinese search engine Baidu and targeted 2 GitHub pages linking to copies of sites that are blocked in the country.

GitHub confirmed that the attack started a few days ago and involved several attack vectors. The world’s largest code host, engaged in supplying social coding tools for developers, revealed that web users’ machines were hijacked to try and bring the service down. Apparently, the intent of this hack is to convince GitHub to remove a specific class of files.

Security experts pointed out that the code particularly targets the pages of two Github users: an organization developing ways to circumvent the “great firewall of China” and the New York Times’ Chinese mirror. The former, GreatFire, achieved some level of success in allowing Chinese residents to bypass the nation’s online surveillance and censorship. The latter aims to allow Chinese residents to read New York Times even if its official website is banned in the country. The mirror offers users an unblockable iOS app and links to further cloud-based copies of the newspaper.

Security researchers say that the attack seemed to be coordinated via code coming from Baidu’s servers. In response, Baidu conducted a thorough investigation and concluded that it was neither a security problem on Baidu’s side nor a hacking attack. The service confirmed that other security organizations joined the efforts to find out the problem.

In the meantime, GitHub’s outages demonstrated the extent to which the supposedly decentralized web depends on a few pieces of critical infrastructure. The service that allows coders to jointly work on software projects from the distance has become a massive web host and a crucial part of other software platforms.

Industry observers note that with GitHub sporadically unavailable over the recent days, companies relying on the service faced problems with deploying new code, which paralyzed their work until the GitHub returns online.