GitHub DDoS attack recorded the largest yet DDoS attack that peaked at 1.35Tbps via 126.9 million packets per second. The Volumetric DDOS attack takes place between 17:21 and 17:30 UTC on February 28th.
With the First wave of attack it peaks up to 1.35Tbps and the wave last for 8 minutes and the second wave of attacks spikes up to 400Gbps after 18:00 UTC.
The GitHub DDoS attack was due to vulnerability via the common misconfiguration in Memcached servers that unique among amplification class of attacks.
Cloudflare says a carefully crafted technique allows an attacker with limited IP spoofing capacity (such as 1Gbps) to launch very large attacks (reaching 100s Gbps) “amplifying” the attacker’s bandwidth.
Github confirms that at no point was the confidentiality or integrity of your data at risk and we are sorry for the impact of this incident.
For attack mitigation, Github moved the traffic through Akamai and the attacked mitigated by reconfiguring the Access Control Lists to filter the packets that pass through the router.
Skottler from Github says “We’re investigating the use of our monitoring infrastructure to automate enabling DDoS mitigation providers and will continue to measure our response times to incidents like this with a goal of reducing mean time to recovery (MTTR)“.
According to DDoS Threat Landscape, the Memcached graph is almost flat and the spike is only just for a couple of the days.
The Memcached is a middleware so it lacks access controls and it should not be exposed to the public Internet, according to Shodan reports there are around 88,000 open Memcached servers found.
Security researchers recommended disabling the UDP support if it is not in use and to place the Memcached servers behind the Firewall. Also, it is recommended to specify Memcached servers to listen only on localhost.