The last 30 days has seen a renewed increase in distributed denial-of-service (DDoS) activity. The list of victims include Amazon, IBM subsidiary SoftLayer, Eurobet Italia SRL, Korea Telecom, HZ Hosting and SK Broadband. The specific type of TCP attack used in the recent spate of DDoS efforts were TCP SYN-ACK reflection attacks. The impact range of these kinds of campaigns is significant, according to Radware, degrading service at the targeted networks as well as reflection networks.
Source: https://threatpost.com/massive-ddos-amazon-telecom-infrastructure/150096/