On February 28, 2018, popular source code hosting web site GitHub was hit by the largest-ever distributed denial of service (DDoS) attack, that peaked at 1.35 Tbps. The attack abused servers running Memcached, an open source distributed memory object caching system. The attack was an amplification attack, where the attacker sends a request of a few bytes to the target server, causing the server to respond with a much larger response, up to 51,200 times larger.
The Github website is protected by the anti-DDoS service provided Akamai.
Read more about it here.