Cloudflare Blocks Largest-Ever DDoS Attack: 37.4 TB in Just 45 Seconds

In an unprecedented cyber event, Cloudflare successfully mitigated the largest Distributed Denial-of-Service (DDoS) attack ever recorded. The assault delivered a staggering 37.4 terabytes of data in just 45 seconds.

Key Details of the Attack:

Type: A massive UDP flood combined with reflection and amplification techniques, using spoofed IP addresses.

Peak Bandwidth: The attack peaked at 7.3 Tbps, a data rate powerful enough to overwhelm major infrastructure almost instantly.

Duration: Although brief, the attack's intensity posed a serious and immediate threat.

How Cloudflare Neutralized the Threat:

Cloudflare leveraged its real-time automated defense systems, including:

Global Anycast Network that distributes traffic load across hundreds of data centers to prevent overload.

Layer 4 Filtering with XDP/eBPF that blocks malicious packets directly at the server level.

Dynamic, Automated Rulesets that respond instantly to abnormal traffic patterns.

The Global Context:

This attack reflects a growing trend of ultra-high-volume, short-duration cyber assaults. In Q1 2025 alone, Cloudflare reported over 700 hyper-volumetric DDoS attacks exceeding 1 Tbps. These attacks are increasingly enabled by vast IoT botnets and more sophisticated exploitation techniques.

Conclusion:

This event underscores the critical importance of having proactive, always-on DDoS protection. The scale and speed of modern cyberattacks leave no room for manual response. For any online business or infrastructure provider, real-time automated mitigation is no longer optional — it’s essential