What are Distributed Denial of Service (DDoS) attacks and how can we protect ourselves from them?

Redazione RHC : 16 July 2025 09:56

Distributed Denial of Service (DDoS) attacks are one of the most common threats to websites, servers, and other online infrastructure. Specifically, this type of attack attempts to overwhelm target servers with a large number of traffic requests, preventing legitimate users from accessing online resources.

In this article, we will examine how DDoS attacks occur, the techniques used today, who carries out the attacks, the solutions made available by cybercrime and how they can be mitigated.

How a Distributed Denial of Service Attack Happens

DDoS attacks are mainly carried out by botnets, which are a collection of computers compromised by malware. These computers, also known as bots, are controlled by a cybercriminal who uses them to send a large amount of anomalous traffic requests to a target server.

This traffic sending process occurs simultaneously and in a coordinated manner across all bots, making it difficult for the server to distinguish legitimate requests from malicious ones. DDoS attacks can be carried out using several methods.

Attack Types and Techniques

There are many forms of attack that allow malicious individuals to compromise the availability of online services by saturating the network or overloading the server. This chapter provides a list of the most common DDoS attack techniques, such as TCP SYN flood, UDP flood, HTTP flood, ICMP flood, and others.

Understanding the different DDoS attack techniques is essential for taking appropriate security measures to mitigate these attacks and protect your online infrastructure. This way, businesses and end users can keep their services available and functioning while protecting their reputation and customer trust.

1. Network-level flooding attack: This attack involves sending a large number of packets across a network to saturate the victim’s bandwidth.
2. Application-level flooding attack: In this attack, the attacker sends a large number of legitimate requests to the victim’s application or website, thus overloading the server’s capacity.
3. Amplification attack: In this attack, the attacker sends a request to a third-party server with a fake IP address of the victim. The third-party server responds with a large amount of data sent to the victim, exploiting the amplification vulnerability.
4. Ping of Death Attack: This attack exploits the ICMP protocol vulnerability by sending large ping packets that exceed the system’s processing capacity.
5. Slowloris Attack: In this attack, the attacker sends incomplete HTTP requests to the server, keeping each connection open for as long as possible, in order to limit the server’s resource availability.
6. DNS Reflection Attack: In this attack, the attacker exploits public DNS servers to send a large volume of spoofed DNS requests to the victim, thus overloading the server. server.
7. HTTP GET attack: In this attack, the attacker sends a large volume of HTTP GET requests to the server, exhausting its capacity to respond.
8. SYN flood attack: In this attack, the attacker sends a large number of SYN connection requests to the server, but does not complete the connection. The server then has to process a large volume of incomplete connections, preventing legitimate connections from accessing.
9. Smurf Attack: In this attack, the attacker exploits the ICMP vulnerability by sending ping packets to a computer network using the victim’s IP address, causing the network to respond with a large amount of incoming traffic.
10. HTTP POST Attack: In this attack, the attacker sends a large volume of HTTP POST requests to the server, overloading its processing capacity.
11. UDP Flood Attack: In this attack, the attacker sends a large number of UDP packets to the server, causing the server to receive a large number of incoming traffic. saturate its processing capacity.
12. TCP reset attack: In this attack, the attacker sends TCP RST packets to the server, terminating active connections.
13. IoT botnet attack: In this attack, the attacker exploits compromised Internet of Things (IoT) devices, such as routers and surveillance cameras, to send large amounts of traffic to the victim.
14. Application layer DDoS attack: In this attack, the attacker sends legitimate requests to a victim’s application or website, but with the goal of overloading the application’s processing capacity rather than the network bandwidth. This attack is often associated with the “slow HTTP attack” technique.
15. Botnet attack: In this attack, the attacker uses a network of compromised computers (botnet) to send a large volume of traffic to the victim, overloading the server’s capacity.

The Motivations of a DDoS Attack

DDoS attacks can be motivated by a variety of reasons, including cyber hacktivism, rivalry between nations or groups, or the desire to extort money.

Cyber hacktivism is a form of online protest that aims to promote a political or social agenda. DDoS attacks are one of the most popular techniques used by hacktivists to disable the websites or online services of organizations or entities they believe are responsible for incorrect or unfair behavior.

Additionally, DDoS attacks can be used as a weapon in international conflicts. For example, during the conflict between Russia and Ukraine, there was a significant increase in DDoS attacks, presumably due to the rivalry between the two nations.

Finally, DDoS attacks can be used as an extortion tactic, particularly after a ransomware attack. In this case, attackers threaten to escalate DDoS attacks unless the victim pays the ransom demanded to restore access to their data.

In general, DDoS attacks are a relatively cheap and easy method of inflicting damage online, and they pose a threat to global cybersecurity. It is important that organizations take appropriate security measures to mitigate DDoS attacks and prevent their systems from being compromised.

What damage does a DDoS attack inflict?

A DDoS attack can cause a range of damage to a computer system or an entire network. Here are some of the possible negative effects of a DDoS attack:

1. Service disruption: A DDoS attack can cause online services, such as websites, applications, or cloud services, to be temporarily inaccessible. This can cause significant financial losses for companies and damage their reputation.
2. Performance degradation: Even if a DDoS attack doesn’t completely disrupt a service, it can still cause performance degradation, slowing response times and causing long wait times. This can negatively impact user experience and customer satisfaction.
3. Data loss: A DDoS attack can be used as a cover for a more advanced cyber attack, such as a data breach. This can lead to the loss of sensitive information, such as personal, financial, or business information.
4. Additional costs: Mitigating the effects of a DDoS attack can incur significant costs for businesses, such as purchasing security tools and the manpower required to address the attack.
5. Reputation issues: A business that suffers a DDoS attack can suffer damage to its reputation, as users may perceive the company’s inability to ensure the security of its services.
6. Security risks: A DDoS attack can also be used to compromise the security of a computer system or network, opening the door to other cyber attacks or malware. This can put not only data security at risk, but also the physical safety of users, as in the case of attacks on industrial control systems or public safety.

How to mitigate DDoS attacks

There are some measures that organizations can take to mitigate DDoS attacks, including “slow HTTP attacks”. Here are some suggestions:

1. Use an anti-DDoS solution: Organizations can use an anti-DDoS solution such as a firewall or an anti-DDoS protection service provided by a managed service provider. These solutions can detect DDoS attacks and block malicious traffic before it reaches the victim’s server.
2. Set up a load balancer: A load balancer can help distribute traffic across multiple servers, preventing overloading a specific server and ensuring a better level of service.
3. Regularly update your software: Ensuring your software and operating systems are updated with the latest security patches can help prevent DDoS attacks that exploit known vulnerabilities.
4. Limit access to services: Reducing the number of services available to the public and limiting access to authorized users can help reduce the impact of a DDoS attack.

For slow http attacks, an anti-DDoS solution that can detect and block malicious traffic packets can be effective, but there are also some other measures that can be useful:

1. Use a web application firewall (WAF): A WAF can help protect web applications from attacks such as slow http attacks by filtering incoming traffic and blocking malicious packets.
2. Configure session timeout: Configuring session timeout to kill idle connections can be helpful. Help prevent “slow http” attacks that exploit slow connections.
3. Use CDN: Using a content delivery network (CDN) can help distribute traffic and mitigate the effects of “slow http” attacks.

In general, organizations should take a variety of security measures to protect their systems from DDoS attacks, and should be prepared to respond quickly in the event of an attack.

What is meant by geolocking

Always within the “Mitigations” of DDoS attacks there is “geolocking”. Geolocking is a technique used to mitigate Distributed Denial of Service (DDoS) attacks by blocking incoming traffic from specific countries or geographic regions.

This technique is based on the idea that DDoS attacks often originate from botnets consisting of infected computers or devices located around the world but concentrated in a limited number of geographic regions. Thus, blocking incoming traffic from these regions can significantly reduce the impact of the DDoS attack on the system or network.

Geolocking can be implemented using various methods, including using firewall software or DDoS mitigation services that allow you to select the geographic regions to block. It is important to note that geolocking is not a complete solution for mitigating DDoS attacks, as it can also block legitimate traffic from users in those geographic regions. Therefore, geolocking should be used with caution and in combination with other DDoS mitigation techniques.

The tools made available by cybercrime

Cybercrime offers various solutions to rent botnets and conduct DDoS attacks, often through the dark web or online underground marketplaces. These solutions include:

1. Botnet-as-a-Service (BaaS): This is a service in which cybercriminals rent their botnets, which consist of a network of infected and remotely controlled devices, to conduct DDoS attacks against their targets. BaaS services can be purchased on online underground marketplaces or through contacts within the hacker community.
2. Stressers and booters: These are paid online services that provide access to a large network of botnets, used to conduct DDoS attacks. These services are often advertised as legitimate tools for testing your website’s resilience, but they are primarily used to conduct DDoS attacks against selected targets.
3. Remote Control Attempt Malware (RAT): This type of malware allows criminals to take control of an infected device, such as a computer or IoT device, and use it as part of a botnet to conduct DDoS attacks.

It is important to note that using these illegal services is punishable by law and can have serious consequences for the individuals involved. Furthermore, organizations must be aware of the existence of these solutions and take the necessary security measures to protect their systems from DDoS attacks.

Conclusions

In conclusion, DDoS attacks represent a serious threat to computer systems and networks. DDoS attacks can be used to shut down online services, render data unavailable, and damage an organization’s reputation. However, several techniques exist to mitigate DDoS attacks, including network-level protection, the use of DDoS mitigation services, and geolocking.

Network-level protection, such as using firewalls and routers with anti-DDoS capabilities, can help filter traffic and protect systems and networks from DDoS attacks. However, network-level protections can be overcome by large-scale DDoS attacks.

DDoS mitigation services, such as those offered by specialized security vendors, can offer more advanced and customized protection against DDoS attacks. These services use sophisticated techniques to analyze network traffic in real time and filter attack traffic, protecting systems and networks from saturation and downtime.

Finally, geolocking can be used to block traffic from specific countries or geographic regions. This technique can reduce the impact of DDoS attacks, but should be used with caution to avoid blocking legitimate traffic from these regions.

In summary, protecting against DDoS attacks requires a multifactorial approach, involving the use of multiple mitigation techniques and the constant evaluation and improvement of network security.