What is a Distributed Denial-of-Service (DDoS) Attack?

DDoS attack meaning

DDoS, short for distributed denial of service, is an attack that makes a site unavailable by overwhelming it with “fake” requests and traffic. This can slow your website or crash the server it is hosted on, which takes down your site as well.

Types of DDoS attacks

The question "What is a DDoS attack?" can have a lot of different answers depending on the type of attack you are talking about. The first step to protecting your organization against DDoS attacks is understanding the type of threats that you face. With that in mind, here are the most common types of DDoS attacks:

Volumetric attacks

Volumetric attacks work by overwhelming the target network with a massive amount of traffic, causing congestion that prevents real users from being able to access the network. Common methods used in volumetric attacks include UDP reflection/amplification and DNS amplification. The goal of these attacks is to saturate the target network so that it is incapable of handling legitimate user requests.

Protocol attacks

Protocol attacks are designed to target network infrastructure by exploiting vulnerabilities in the network protocols. Commonly targeted protocols include ICMP, TCP, and UDP. With a protocol attack, hackers can manipulate these protocols in a way that forces the target systems to expend resources on handling illegitimate or malformed packets, which leads to service disruption.

Application-layer attacks

Unlike volumetric and protocol attacks, application-layer attacks are meant to target the application layer of a network. These attacks work by exploiting vulnerabilities in web applications or services and are designed to exhaust server resources by overwhelming them with a large number of requests. Examples of application-layer attacks include HTTP floods, slowloris attacks, and SQL injection attacks.

Fragmentation attacks

Fragmentation attacks work by manipulating packet fragments in order to overwhelm the target system. By sending incomplete or overlapping packets, hackers attempt to confuse the target system's ability to reassemble the data correctly. This can lead to a degradation of network performance and can potentially disrupt communication between systems.

Amplification attacks

With an amplification attack, hackers use third-party systems to magnify the volume of traffic they are able to direct at a target system. These attacks exploit vulnerabilities in services that respond with larger data packets than the initial request, which enables hackers to amplify the impact of their DDoS attack. Common amplification techniques include DNS amplification, NTP amplification, and SSDP amplification.

Zero-day exploits

This is a unique category of DDoS attacks. It encompasses any type of DDoS attack that exploits vulnerabilities unknown to the target and the cybersecurity community. Hackers are constantly searching for opportunities to capitalize on undisclosed vulnerabilities since it allows them to take advantage of the absence of available patches or defenses. These zero-day exploits underscore the immense importance of remaining vigilant and employing proactive security measures.

DoS vs. DDoS attacks

Though often confused, Denial of Service (DoS) attacks and Distributed Denial of Service (DDoS) attacks are actually two different types of cyber threats. Both of these attacks are designed to overwhelm the target system and disrupt its performance, but they go about it in different ways.

DoS attacks are orchestrated from a single source (or a small number of sources), which typically makes it easier to identify and mitigate the threat. DDoS attacks, on the other hand, take a more sophisticated approach by leveraging multiple sources, often coordinated through a botnet. This amplifies the scale and impact of the attack while also making it more difficult to detect and mitigate.

Motivations behind DDoS attacks

Unlike many types of cyber attacks, DDoS attacks are not intended to steal data from the target. Instead, they are simply designed to disrupt and damage a targeted organization.

This is sometimes done for revenge or as a form of "hacktivism". In other cases, DDoS attacks are launched as a means of gaining a competitive advantage over a business. Sometimes, DDoS attacks are also used to extort a business, similar to ransomware attacks, with hackers promising to halt the attack once a ransom is paid.

Impact on businesses

Downtime can be devastatingly expensive for small and medium-sized businesses (SMBs). Website downtime can cost as much as $427 per minute, and DDoS attacks cost an average of $120,000.

DDoS attacks are also favored by cybercriminals because they are extremely inexpensive and can be purchased online for as little as a dollar a minute. Unfortunately, once you’re a target, you’re likely to be attacked again – studies show that two-thirds of all DDoS targets were hit repeatedly.

Along with these significant financial impacts, DDoS attacks can also permanently damage a business's reputation and the trust its customers have in it; if a DDoS attack renders your business unable to serve its customers, they often look elsewhere for their needs and may never come back.

DDoS mitigation

DDoS attacks can be devastating, but the good news is that they can also be largely prevented and mitigated with the right cybersecurity protocols and solutions. If you would like to bolster your business's defenses against DDoS attacks, here are a few proven methods to employ:

Use DDoS protection services like a WAF

Implementing DDoS protection services such as traffic filtering mechanisms, real-time monitoring, and a web application firewall (WAF) is one of the most effective ways to mitigate DDoS attacks. WAFs are particularly useful for preventing DDoS attacks, as they are designed to automatically analyze HTTP traffic and block any traffic that is deemed potentially malicious.

Segment your network to limit the impact of an attack

Segmenting your network into isolated sections can greatly limit the impact of a DDoS attack. By compartmentalizing resources and services, you can structure your network in a way that makes an attack on one segment much less likely to affect the entire network. This helps keep critical services operational even during an ongoing attack.

Increase bandwidth and scalability with a CDN

A content delivery network (CDN) enables you to distribute your online content across multiple servers worldwide. Along with reducing latency and enhancing the overall performance of your network, CDNs are also capable of absorbing a significant portion of DDoS traffic to reduce the impact of the attack.

Implement rate limiting and access controls

Rate limiting and access controls can both help regulate the flow of incoming traffic. Setting limits on the number of requests a user or IP address can make within a specific time frame can help prevent DDoS attacks. Strong access controls, meanwhile, allow you to restrict access to specific resources, preventing hackers from exploiting vulnerabilities.

Regularly update and patch systems for vulnerabilities

Keeping your systems up to date with the latest security patches is a cornerstone of effective cybersecurity. Regular updates and patching can help close known vulnerabilities that hackers may otherwise exploit, and this proactive approach helps ensure that your infrastructure is resilient against DDoS attacks and other security threats.

Stop DDoS threats with SiteLock

The potential impact of DDoS attacks is something that businesses cannot afford to take lightly. Thankfully, SiteLock offers cutting-edge cybersecurity solutions that businesses need to stay protected.

From web application firewalls for filtering incoming traffic to real-time network monitoring to a content delivery network for boosting your network's performance and reliance, SiteLock takes a modern, wide-ranging approach to defending against DDoS attacks in all their various forms.

To get started protecting your business from DDoS attacks and other cyber threats, be sure to learn how SiteLock works, and check out our affordable pricing packages!

Frequently asked questions

Interested in learning more about DDoS attacks? Here are the answers to some of the most commonly asked questions about these attacks:

Are DDoS attacks illegal?

Yes, DDoS attacks are illegal. Attempting to overwhelm an organization's online services or otherwise disrupting their normal operations is a violation of computer security laws in many jurisdictions, and perpetrators of DDoS attacks can face criminal charges, fines, and imprisonment.

How long will a DDoS attack last?

The duration of a DDoS attack can vary significantly. Some attacks are short-lived, lasting only minutes, while others can last for hours or even days. The length of an attack depends on factors such as the attackers' motives, resources, and the effectiveness of the targeted organization's DDoS mitigation measures.

How do you detect a DDoS attack?

The most effective way to detect a DDoS attack is by monitoring network traffic for unusual patterns or sudden spikes in volume. Signs of a DDoS attack may include a significant increase in the number of requests, a slowdown in website performance, or unavailability of online services.

Are DDoS attacks traceable?

Due to the distributed nature of DDoS attacks, tracing their origin can often be challenging. Hackers launching DDoS attacks will commonly use botnets or anonymization techniques to hide their identity. However, analyzing the attack traffic can still provide useful insights into the methods that were employed.

How common are DDoS attacks?

DDoS attacks have become regrettably common in a world where so many organizations are heavily reliant on their online services; it is estimated that there were 5.2 million DDoS attacks launched in 2023 alone, and organizations of all sizes can potentially end up being targeted.

What country do most DDoS attacks come from?

DDoS attacks can originate from almost anywhere. According to Cloudflare, more DDoS attacks originate from China than any other country, followed by the United States, Brazil, India, and Malaysia.