Cloudflare Thwarts Record-Breaking 7.3 Tbps DDoS Attack on Hosting Provider

TL;DR

Cloudflare successfully mitigated a record-breaking 7.3 Tbps DDoS attack in May 2025, showcasing the robustness of its DDoS protection solutions. The attack targeted a hosting provider and underscores the escalating scale of cyber threats.

Cloudflare’s Landmark Defense Against Record-Breaking DDoS Attack

Cloudflare recently demonstrated its prowess in cybersecurity by blocking a record-breaking 7.3 Tbps DDoS attack in May 2025. This incident marks a significant escalation in the scale of such attacks, surpassing previous records by a notable margin.

Overview of the Attack

Magnitude and Impact

The attack peaked at 7.3 Tbps, which is 12% higher than any previous DDoS attack mitigated by Cloudflare. It also surpassed the 6.3 Tbps attack reported by cyber journalist Brian Krebs¹.

Target and Duration

The primary target was a Cloudflare customer—a hosting provider utilizing Cloudflare’s DDoS protection solution, Magic Transit. The attack blasted 37.4 TB of data in just 45 seconds, equivalent to streaming 9,350 HD movies or downloading 9.35 million songs in under a minute.

Attack Characteristics

The DDoS attack was multivector, with 99.996% comprising UDP floods. Other vectors included QOTD, Echo, NTP, Mirai, Portmap, and RIPv1 attacks. The attack originated from 122,145 IPs across 5,433 networks in 161 countries, with nearly half coming from Brazil and Vietnam.

Effectiveness of Cloudflare’s DDoS Protection

Cloudflare’s systems successfully blocked the attack autonomously, without requiring human intervention or triggering alerts. This success underscores the effectiveness of Cloudflare’s DDoS protection mechanisms.

Previous Record Attack

The previous record attack blocked by Cloudflare reached 5.6 Tbps and occurred during the week of Halloween 2024. This attack, launched by a Mirai-variant botnet, targeted an Internet service provider (ISP) in Eastern Asia and lasted only 80 seconds².

Cloudflare’s Commitment to Cybersecurity

Cloudflare’s ability to mitigate such large-scale attacks highlights its commitment to providing robust cybersecurity solutions. The company’s advanced systems ensure that protected hosting providers and other customers remain secure against escalating cyber threats.

Additional Resources

For further insights, check:

• Cloudflare’s Blog on the 7.3 Tbps DDoS Attack
• Krebs on Security

References

1. Brian Krebs (May 2025). “KrebsonSecurity Hit With Near-Record 6.3 Tbps DDoS”. Krebs on Security. Retrieved June 20, 2025. ↩︎

2. Security Affairs (October 2024). “Cloudflare Blocked Record 5.6 Tbps DDoS Attack”. Security Affairs. Retrieved June 20, 2025. ↩︎