What is a DDos Attack?

A Distributed Denial of Service (DDoS) attack is designed to force a website, computer, or online service offline, by disrupting network services in an attempt to exhaust an application’s resources. This is accomplished by flooding the target with many requests, consuming its capacity and rendering it unable to respond to legitimate requests. Certain industries, such as gaming, e-commerce, and telecommunications, are targeted more than others.

How DDoS attacks work

A DDoS attack is essentially the legitimate use of an online service taken too far. For example, a website may be capable of handling a certain number of requests per minute. If that number is exceeded, then the website’s performance is degraded, or it may be rendered completely inaccessible. This can be achieved mainly through a series of bots, or botnets, flooding a website or service with HTTP requests and traffic pushing out legitimate users.

Types of DDoS attacks

1. Amplification/Volumetric Attacks: attackers will send a request to a DNS server with their IP address spoofed to the IP address of the target, causing the target to receive a large volume of unsolicited responses that eat up resources.
2. Bandwidth Saturation: Bandwidth saturation attacks attempt to consume the maximum bandwidth and throughput that a network can maintain with spam traffic.
3. Application-Layer Attacks: Often referred to as a Layer 7 DDoS attack (application-layer) where web pages are generated in response to Hypertext Transfer Protocol (HTTP) requests by exhausting or overwhelming the target's resources.

DDoS Attack Prevention and Protection

1. Risk Assessment: regularly conduct risk assessments and audits to identify gaps in security and assess potential threats in the systems.
2. Traffic Differentiation: determine the quality or source of the abnormal traffic by use of the Anycast network to scatter the attack traffic across a network of distributed servers. This is performed so that the traffic is absorbed by the network and becomes more manageable. Content Delivery Network (CDN) also helps distribute content across multiple servers and locations to reduce the impact of an attack.
3. Rate Limiting: Limiting the number of requests a server can accept within a specific time frame from a single IP address or a specific geographical region to prevent attackers from overwhelming the system.
4. Intrusion Prevention Systems (IPS): IPS helps to identify and block malicious traffic in real-time through the identification of unusual traffic patterns. Use of Web Application Firewall (WAF) which sits between the internet and a company's servers and acts as a reverse proxy and creates a set of rules that filter requests.

Conclusion

DDoS attacks pose a significant threat to the availability of online services. Implementing a comprehensive cybersecurity strategy that includes preventive measures, detection mechanisms, and effective response plans is crucial for minimizing the impact of DDoS attacks.