The largest DDoS attack in GitHub.com s history began March 25. GitHub officials believe the attack is part of an effort to force the company to remove some content. The attack began around 2AM UTC on Thursday, March 26, and continues over the weekend. GitHub has implemented volumetric defenses to help defeat the attack, but the effects were temporary. Researchers looking at the attack discovered that the attackers apparently were using scripts placed around the Web were hijacking Baidu traffic to flood GitHub.
Source: https://threatpost.com/ddos-attack-against-github-continues-after-more-than-four-days/111891/