DDoS threats: analysis, defense against attacks, and preventive strategies

17 April 2024

Information security and the availability of online services have become key pillars of our privacy and business stability. In this context, DDoS (Distributed Denial of Service) attacks are one of the most destructive forms of cybercrime – they can paralyze not only home Internet but also affect the operations of companies, governments, and non-profit organizations. Over the past decades, DDoS attacks have evolved, becoming more complex and harder to neutralize. Understanding their mechanism is crucial for anyone operating in today’s Internet, which is why we decided to bring you closer to this topic.

Definition of DDoS: What is a DDoS attack?

A DDoS attack (distributed denial of service) is a type of cyberattack in which many infected internet hosts, called bots, are used to intentionally overload the target system or network. Typically, these bots are part of a larger network called a botnet, controlled by the attacker. A botnet can consist of thousands or even millions of infected computers, which can be spread worldwide.

A DDoS attack involves sending massive amounts of fake network traffic to the victim, including fake requests to servers, overloading ports and network interfaces. As a result, excessive traffic significantly slows down the server’s speed or completely blocks access to it, preventing regular users from accessing key services and applications. The effects of such an attack can be devastating: often leading to financial losses, damage to reputation, and prolonged service outages.

A Brief Introduction to the History of DDoS Attacks

DDoS attacks are not new to the internet world; their origins can be traced back to the 1990s. The first incidents were relatively simple in their construction and execution. One of the first widely known DDoS attacks was the attack on the University of Minnesota on July 22, 1999. On that day, 114 computers infected with the Trin00 script flooded the university’s server with massive amounts of network traffic, taking it offline for two days.

Since then, DDoS attacks have become more destructive and sophisticated. The increase in the number of internet-connected devices, such as smartphones and IoT devices, has given cybercriminals a larger playing field and complicated defense against attacks. A significant turning point was Operation “Payback” conducted in 2010 by a group of hackers known as Anonymous. They targeted several major financial institutions and entertainment companies, demonstrating how powerful DDoS attacks can be and the enormous losses they can cause.

Today, DDoS attacks use advanced techniques such as DNS and NTP amplification to generate even more traffic. Modern attacks can last for weeks and are very often directed against the largest enterprises and critical infrastructure.

How Do DDoS Attacks Work?

DDoS attacks are particularly harmful due to their high efficiency in disrupting the operation of online services and network infrastructure. Understanding how they are conducted is crucial for implementing effective defense strategies. Here, we will explain how DDoS attacks work.

Technical Description: How Are DDoS Attacks Conducted?

Every DDoS attack begins with building or renting a botnet, which is a network of infected devices, called bots. Attackers can gain control over devices through various methods: phishing, exploiting software vulnerabilities, or malware. Once infected, these devices, often without their owners’ knowledge, become part of the botnet.

After setting up the botnet, the attacker initiates the attack by commanding their bots to send large amounts of network traffic or data requests to a specific target. This traffic can take the form of legitimate requests to the server, as in application layer attacks, or consist of fake packets and queries to overwhelm the network infrastructure.

A typical tactic is the asymmetry between the small amount of data the attacker needs to send and the large amount of data the target must process. For example, the attacker might send a request that requires the server to perform a complex operation or generate large amounts of data, quickly exhausting the targeted system’s resources.

Cybercriminals conducting a DDoS attack
Photo: Cybercriminals conducting a DDoS attack

Different Types of DDoS Attacks: Explanation of the Most Commonly Used Methods

DDoS attacks can be divided into several types depending on the technique used and the targeted layer of the OSI (Open Systems Interconnection) model. Here are some of the most commonly used methods:

  1. Volumetric Attacks: the simplest form of DDoS attack, involving flooding the target with massive amounts of network traffic. The goal is to saturate the victim’s internet bandwidth, preventing proper handling of traffic. An example is the UDP flood attack.
  2. Protocol Attacks: focus on exploiting weaknesses in network and transport layer protocols, such as IP, TCP, and UDP. An example of such an attack is the SYN flood, where the attacker sends a series of TCP connection requests to the target, never completing the connection process.
  3. Application Layer Attacks: are more sophisticated, targeting specific applications or services of the victim. These attacks are harder to detect and defend against, as they generate traffic that can look like normal user requests. A typical example is the HTTP flood attack.
  4. Asymmetric Attacks: utilize server responses that are significantly larger than the request sent, increasing the amount of traffic the target must process. A typical example is the DNS amplification attack, where a query for a few bytes of DNS record can generate a response of several megabytes.

Understanding the methods of conducting DDoS attacks allows for better preparation for defense and planning appropriate countermeasures. This may include software for detecting and mitigating DDoS attacks, as well as resource distribution or increasing network bandwidth.

Motivations Behind DDoS Attacks

Understanding the motivations behind DDoS attacks is crucial for developing effective defense strategies and accurately assessing the risk of compromising our network security. DDoS attacks are conducted for a variety of reasons, from financial to ideological.

Why Are DDoS Attacks Conducted?

  1. Ransom: One of the most common reasons for conducting DDoS attacks is ransom. Attackers paralyze the operation of online services or network infrastructure and then demand payment to stop the attack. Companies that depend on the continuous availability of their online services are particularly vulnerable to such attacks.
  2. Political Motivations and Activism (Hacktivism): DDoS attacks are often used as a form of digital protest. Activist groups may use DDoS attacks to express opposition to the policies of governments, international organizations, or specific companies. Examples include attacks conducted by the Anonymous group, which often aimed to draw attention to social or political issues.
  3. Business Competition: Some DDoS attacks may be sponsored by competing companies seeking to disrupt the operations of a rival. Although such actions are illegal, there have been cases of using DDoS attacks as a tool in business wars.
  4. Demonstration of Power: Some cybercriminals use DDoS attacks to demonstrate their power on the Internet, which can serve as a form of advertising their services in the criminal world. Criminals offer their services as ‘DDoS-for-hire,’ allowing others to rent their capabilities to conduct attacks.
  5. Diversion: DDoS attacks can also be used as a smokescreen to divert attention from other criminal activities, such as data theft from the target’s servers.

Examples of Known Attacks and Their Motivations

  • Attack on PayPal in 2010: Conducted by the Anonymous group as part of Operation “Payback.” This attack was a form of protest against PayPal’s decision to block payments to WikiLeaks. The goal of the attack was to draw media attention to issues of freedom of speech.
  • Attacks on Estonian Institutions in 2007: These are believed to have had political motivations. Estonia experienced massive DDoS attacks following the controversial relocation of the Bronze Soldier, a Soviet war memorial. The attacks paralyzed banks, government services, and media outlets. This case is still intensely studied by many countries and military planners.
  • Attack on Dyn in 2016: This was a widespread DDoS attack that disrupted many large websites, including Twitter, Netflix, and Amazon. The attack was carried out by the New World Hackers group and is believed to have been a demonstration of power by ‘DDoS-for-hire‘ service vendors. Over 100,000 bots were used in the attack. It is considered one of the largest DDoS attacks in history.
DDoS Attack on Dyn
Photo: Effects of the DDoS Attack on Dyn / Source: Wikipedia

Impact of DDoS Attacks

DDoS attacks can have serious and often long-lasting consequences for both companies and individual Internet users. Here, we will look at how DDoS attacks affect companies and internet users.

  1. Service Disruptions: The most direct and obvious effect of a DDoS attack is the loss of availability to websites and online services. For companies that rely on e-commerce, this means immediate financial losses.
  2. Reduced Trust and Reputation: Prolonged or repeated attacks can lead to a loss of customer trust and damage the company’s reputation. Customers who experience issues accessing services or fear for the security of their data may choose to stop using the services of the affected company.
  3. Increased Operational Costs: Companies must invest in advanced DDoS protection systems, which can significantly increase operational costs. Following an attack, companies may incur additional costs for incident analysis, service restoration, and communication with customers.
  4. Production Downtime: For manufacturing and operational companies that rely on systems and network infrastructure, DDoS attacks can lead to production downtimes. This generates additional costs related to delivery delays and potential contractual penalties.
  5. Threat to Data Security: Although DDoS attacks themselves typically do not lead to data breaches, they can be used as a smokescreen to mask more malicious activities, such as data theft.

Analysis of Short-term and Long-term Effects of DDoS Attacks on Business Operations.

Short-term Effects:

  • Immediate loss of access to critical applications and services.
  • Disruptions in communication with customers and business partners.
  • The need for rapid crisis response, which can divert resources from other important projects and operations.

Long-term Effects:

  • Permanent loss of customers who switch to competitors seeking more reliable options.
  • Increased costs associated with investments in better security and IT infrastructure.
  • Potential legal consequences, including penalties for failing to meet SLAs (Service Level Agreements) and breaches of data protection regulations.
  • Decrease in the company’s stock value and potential difficulties in attracting investors.

Protection Against DDoS Attacks

Protection against DDoS attacks requires a comprehensive approach encompassing both technology and good operational practices. Below, we discuss key defense methods and the importance of safeguards in preventing DDoS attacks.

What are the Available Methods for Defending Against DDoS Attacks?

  1. Geographic Distribution of Resources: One way to mitigate the risk of a DDoS attack is to distribute data and applications across multiple servers in different geographical locations. Such distribution can help absorb the excessive network traffic generated during an attack.
  2. Load Balancing: Load balancing systems can evenly distribute network traffic among multiple servers, preventing the overload of a single access point. This reduces the risk that an attack on one domain or server will impact the entire infrastructure.
  3. Network-level Protection: Internet service providers can protect customers from DDoS attacks by filtering traffic directed at a specific IP address. They can also use solutions that help filter unwanted traffic before it reaches the company’s network.
  4. Hybrid Defense Solutions: Using both local and cloud-based security can increase flexibility in defending against DDoS attacks. The cloud can offer additional resources, processing capabilities, and the ability to disperse DDoS attacks.
  5. Web Application Firewall (WAF): Web application firewalls can protect servers from application layer attacks by identifying and blocking malicious requests. WAFs are effective against many DDoS attacks, especially those targeting specific application vulnerabilities.
  6. Planning and Simulations: Regularly conducting DDoS attack simulations can help assess resilience to such events and identify areas that need strengthening.
Managing a botnet from a basement
Photo: Managing a botnet from a basement

Natural Phenomena Resembling DDoS Attacks

Understanding DDoS attacks would not be complete without mentioning situations that naturally resemble their effects, although they are not caused by malicious actions. One such case is the increased number of visits to a website, which often occurs during major online promotions or events that attract massive attention.

The Phenomenon of Increased Traffic on Websites

  1. Promotions and Sales: Online stores, especially those offering attractive discounts during events like Black Friday or Cyber Monday, often experience a significant surge in traffic. Many users simultaneously try to access the same deals, which can lead to server overload.
  2. Product Launches: The release of a new, highly anticipated product, such as the latest smartphone model or a popular video game, can also generate a spike in interest. Product pages and online stores may be flooded with requests, sometimes resulting in slowdowns or crashes.
  3. Media Events: Live broadcasts of important events, such as award ceremonies or sports events, can attract a massive number of viewers, which is demanding for hosting infrastructure.

Managing Increased Internet Traffic

Similar to defending against DDoS attacks, managing natural traffic spikes requires preparation and the implementation of appropriate technological solutions:

  1. Scalable Infrastructure: Using flexible cloud solutions that allow for quick scaling of resources in response to increased demand is crucial for maintaining service availability.
  2. Resource Optimization: Improving server performance through database optimization, effective page caching, and minimizing complex queries can significantly enhance page loading speed during high traffic periods.
  3. Load Balancing: Utilizing advanced load balancing systems that evenly distribute traffic across servers prevents the overload of a single point and ensures better user service.


DDoS attacks are one of the biggest threats on the Internet, affecting businesses, governments, and internet users worldwide. In this article, we have presented a comprehensive view of DDoS attacks, starting from their definition, through the methods of execution, motivations of perpetrators, impact on business operations, and defense methods.

The variety of perpetrator motivations, from financial to ideological, makes each attack unique and requires an individualized approach to detection and defense.

Defending against DDoS attacks requires both advanced technological solutions and good operational practices. Scalable infrastructure, advanced monitoring systems, and regular testing form the foundation of effective protection.

With the increasing use of artificial intelligence and the growing number of Internet-connected devices, we can expect DDoS attacks to continue evolving. In response to these challenges, defense strategies must also develop.

Preparing to repel DDoS attacks requires continuous attention and investment in modern technologies and defensive strategies. This is essential to ensure security in an ever-changing digital world.

Sources and References

The article uses information from the following sources:

  1. DDoS on Wikipedia: https://pl.wikipedia.org/wiki/DDoS
  2. The first DDoS attack was 20 years ago. This is what we’ve learned since: https://www.technologyreview.com/2019/04/18/103186/the-first-ddos-attack-was-20-years-ago-this-is-what-weve-learned-since/
  3. Operation Payback on Wikipedia: https://pl.wikipedia.org/wiki/Operacja_Payback
  4. 2007 cyberattacks on Estonia on Wikipedia: https://en.wikipedia.org/wiki/2007_cyberattacks_on_Estonia
  5. 2016 Dyn cyberattack on Wikipedia: https://pl.wikipedia.org/wiki/Cyberatak_na_Dyn
  6. What is DDoS-for-Hire?: https://www.atera.com/glossary/ddos-for-hire/