DDoS (Distributed Denial of Service)
A DDoS (Distributed Denial of Service) attack is a cyberattack that floods a target server, network, or application with massive volumes of traffic from multiple distributed sources, rendering it slow or completely unavailable to legitimate users. Unlike a simple DoS attack from a single source, DDoS attacks use botnets of thousands or millions of compromised devices to generate traffic volumes that overwhelm even well-provisioned infrastructure.
How DDoS Attacks Work
DDoS attacks exploit the fundamental limitation that every server has finite capacity. Attackers build botnets by infecting computers, IoT devices, and servers with malware that allows remote control. When an attack is launched, all compromised devices simultaneously send requests to the target, consuming bandwidth, CPU, memory, or application resources until the service cannot respond to legitimate traffic.
Attacks fall into three main categories. Volumetric attacks flood network bandwidth with massive data streams, often using DNS amplification or UDP floods. Protocol attacks exploit weaknesses in network protocol stacks, such as SYN floods that exhaust connection tables. Application-layer attacks target specific services like HTTP, sending requests that appear legitimate but are designed to consume server resources.
Impact on Businesses
The cost of DDoS attacks extends far beyond downtime. Ecommerce sites lose revenue for every minute they are offline. SaaS providers face SLA violations and customer churn. Financial services firms risk regulatory consequences. The average cost of a DDoS attack is estimated at $20,000-$40,000 per hour, factoring in lost revenue, remediation costs, and reputational damage.
DDoS attacks are also increasingly used as smokescreens to distract security teams while attackers execute data breaches or ransomware deployments through other vectors.
Protection Strategies
Effective DDoS mitigation requires multiple layers. CDNs like Cloudflare and Akamai absorb volumetric attacks by distributing traffic across global edge networks. Rate limiting restricts the number of requests a single IP address can make within a time window. Firewalls filter malicious application-layer traffic. Cloud-based DDoS protection services can scrub traffic in real time, forwarding only legitimate requests to your origin server.
Proactive monitoring is equally important. Use website monitoring software to detect traffic anomalies and trigger mitigation before an attack fully impacts your services.
