Analysis of the Record‑Breaking 1.23 Tbps DDoS Attack Mitigated by Tencent Cloud

The article describes a massive DDoS attack that occurred on April 8, targeting a Tencent Cloud‑hosted card‑game customer, with a peak traffic of 1.23 Tbps – the largest known attack volume in China at that time.

The attack consisted mainly of bandwidth‑congestion SSDP reflection (≈97 % of traffic) and a smaller portion of protocol‑flaw SYN/ACK floods (≈3 %). SSDP reflection works by IP‑address spoofing: attackers forge the victim’s IP and send requests to open SSDP services; the services, unable to verify the request, reply to the victim, and under certain conditions each request can be amplified up to ~30×, generating huge traffic volumes.

Source‑IP analysis showed 166 000 distinct attackers, 68 % domestic and 32 % overseas. Within China the main provinces were Shandong (40 %), Liaoning (20 %), Hebei (16 %), followed by Zhejiang and Taiwan. The primary ISPs were China Telecom (66 %) and China Unicom (24 %). Attackers originated largely from personal PCs (57 %), IDC servers (28 %), and IoT devices (15 %), highlighting the growing role of insecure IoT in DDoS campaigns.

To defend against such attacks, the article recommends that game operators (1) evaluate attack risk and, if needed, subscribe to anti‑DDoS high‑protection services; (2) after enabling high‑protection, hide the origin server IP to prevent direct hits; and (3) tailor protection policies to business specifics—block unnecessary ports/protocols, configure CC protection for HTTP traffic, and consult the Tencent Cloud Game Security team for deep‑custom strategy, especially for private protocols or multilayer CC attacks.

The conclusion stresses that wherever there is profit and internet connectivity, DDoS threats persist. Early risk assessment, choosing a trustworthy cloud provider, purchasing high‑protection when necessary, and working with expert teams to devise customized defenses are essential for safeguarding game services.