DDoS detection gaps: are your controls catching attacks early?

TL;DR: About 85% of observed DDoS attacks lasted less than twenty minutes, and nearly 73% of detected attacks stayed between 0.0 and 0.5 Gbps, which makes early identification central to reducing downtime, according to DigiCert. Fast detection changes DDoS from a black swan outage into a containable availability incident.

NHIMG editorial — based on content published by DigiCert: Early DDoS Detection: Your First Line of Defense

By the numbers:

• Approximately 85% of observed DDoS attacks lasted less than twenty minutes.

Questions worth separating out

Q: How should security teams detect DDoS attacks before users notice an outage?

A: Use layered monitoring that combines traffic telemetry with service performance data.

Q: Why do short DDoS attacks still create serious operational risk?

A: Short attacks are often probes, not the full campaign.

Q: What signals indicate a DDoS event is moving from probe to escalation?

A: Watch for rising traffic from unfamiliar IP ranges, repeated handshake failures, new geographic clusters, increasing application errors, and growing latency.

Practitioner guidance

• Baseline traffic against service health together Correlate NetFlow or sFlow with SNMP, synthetic transactions, RUM, and APM so unusual traffic and user-facing degradation are visible in the same monitoring view.
• Tune alerts for low-volume reconnaissance Lower the threshold for investigating short bursts, incomplete handshakes, unusual geography, and off-hours spikes because many attacks remain below obvious bandwidth alarms.
• Pre-authorise mitigation paths Document when to trigger rate limiting, selective IP blocking, traffic shaping, DNS diversion, or BGP-based scrubbing so responders do not improvise under pressure.

What's in the full article

DigiCert's full blog covers the operational detail this post intentionally leaves for the source:

• Specific telemetry combinations used for detection, including how NetFlow, sFlow, and SNMP are applied in practice
• Concrete examples of DDoS indicators such as incomplete TCP handshakes, geography anomalies, and application error patterns
• Response differences between always-on and on-demand mitigation workflows, including activation behaviour and notifications
• Implementation detail on how DigiCert UltraDDoS Protect applies detection and alerting in real time

👉 Read DigiCert's analysis of early DDoS detection and response →

DDoS detection gaps: are your controls catching attacks early?

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