1.5 Gpps UDP Flood Shakes Scrubbing Provider With Record DDoS

FastNetMon has confirmed detection of a record-scale Distributed Denial of Service (DDoS) attack, peaking at 1.5 billion packets per second (Gpps). The assault, targeting a European DDoS scrubbing provider, is one of the highest packet-rate floods ever disclosed publicly.

While not the largest in raw bandwidth, the event highlights the evolving threat of packet-saturation attacks designed to overwhelm router CPU, control planes, and scrubbing pipelines rather than transit links.

Attack Profile

The attack was not a conventional volumetric flood but a massive UDP-based packet storm launched from globally distributed compromised devices.

Vector: UDP flood targeting scrubbing infrastructure.
Scale: 1.5 Gpps peak rate.
Bandwidth: Lower than multi-Tbps volumetric floods, but optimized for packet-per-second impact.
Origin: Over 11,000 autonomous networks contributed traffic.
Botnet composition: Large clusters of compromised MikroTik routers and IoT devices, acting as customer premises equipment (CPE).

This methodology indicates adversaries are prioritizing state-exhaustion vectors over pipe saturation, aiming at router forwarding engines, ACL tables, and scrubbing CPUs.

Detection Mechanisms

FastNetMon’s flow telemetry analysis platform, written in optimized C++, enabled near-real-time detection. Critical elements:

Flow-based anomaly detection: Identifying packet-rate anomalies at the millisecond scale.
CPU-efficient algorithms: Parsing billions of NetFlow/IPFIX records without loss.
Real-time signaling: Immediate trigger of defensive ACLs and scrubbing workflows.

Detection latency is crucial in Gpps-scale attacks, where control plane resources can be exhausted within seconds.

Mitigation Strategies

Mitigation combined automated filtering, rate-limiting, and scrubbing workflows:

Access Control Lists (ACLs) deployed on upstream edge routers to discard obvious spoofed traffic.
Scrubbing center packet inspection, including UDP state analysis and anomaly detection.
Dynamic blackholing for unmitigable subnets, sacrificing reachability to preserve upstream stability.
Rate-limit enforcement for specific UDP ports leveraged in amplification or flood scenarios.

While effective in this instance, the reliance on ACLs at such scale exposes edge router performance bottlenecks. ACL deployment at 1.5 Gpps stresses TCAM capacity and control plane update cycles.

Strategic Implications

This event represents a paradigm shift in attacker priorities:

From bandwidth to packet-rate: Threat actors are engineering floods to stress packet processing pipelines, bypassing traditional bandwidth-centric defenses.
CPE exploitation: The reliance on compromised routers and IoT devices underscores persistent firmware negligence and default credential exploitation.
ISP responsibility: Filtering at the ISP level is essential; without outbound UDP controls, infected CPEs become unfiltered launchpads.
Scrubbing resilience: Providers must scale to handle not just Tbps floods but multi-Gpps packet rates.

Comparative Context

Other recent incidents highlight the dual evolution of attack methodologies:

Cloudflare mitigation (2025): Reported 11.5 Tbps, 5.1 Bpps floods, prioritizing volumetric scale alongside packet-rate stress.
FastNetMon detection (2025): Emphasis on packet-rate intensity at 1.5 Gpps, demonstrating adversaries can weaponize smaller devices at massive distribution scale.

Comparison Snapshot:

Attack Event	Scale	Nature	Key Target	Implication
Cloudflare (2025)	11.5 Tbps / 5.1 Bpps	Volumetric + packets	Edge pipes	Bandwidth exhaustion
FastNetMon (2025)	1.5 Gpps	Pure packet flood	Scrubbing	Control plane exhaustion

This dual trend suggests defenders must build multi-layered resilience: bandwidth mitigation and packet-rate scaling.

Recommendations

For ISPs

Implement egress filtering (BCP38/BCP84) to suppress spoofed UDP from customer networks.
Deploy telemetry pipelines for per-subscriber packet-rate anomaly detection.
Maintain ACL automation frameworks capable of near-instant deployment at line rate.

For Scrubbing Providers

Architect scrubbing centers with packet-rate scaling in mind, not just raw bandwidth capacity.
Offload filtering to programmable ASICs and FPGA-based platforms to avoid CPU bottlenecks.
Invest in low-latency telemetry triggers that initiate mitigation before exhaustion thresholds are hit.

For Device Vendors & Enterprises

Enforce secure defaults: no factory default passwords, minimal UDP exposure.
Ensure firmware patch pipelines for consumer routers and IoT devices.
Promote carrier-grade automatic update mechanisms for widely deployed CPE.

The 1.5 Gpps flood detected by FastNetMon is a milestone in DDoS evolution. It highlights a new generation of threats where packet processing exhaustion is prioritized over bandwidth saturation. With IoT and CPE devices weaponized into global botnets, the defensive burden shifts to ISPs, scrubbing providers, and device vendors alike.

Without systemic adoption of ISP-level egress filtering, firmware hardening, and packet-rate aware scrubbing infrastructure, the next wave of Gbps-scale floods could cripple even the most prepared networks.

This incident should be treated not as an outlier but as a preview of the coming normal in high-velocity, distributed denial-of-service warfare.