DoS and DDoS attacks: where did they come from, their consequences, and basic rules of website protection

Suddenly, your website stops working, servers are unresponsive, and users complain about errors? Most likely, you have become the target of a DoS attack. But where do these threats come from, how do they work, and what can you do to protect your website? We will tell you further.

In this article, you will find useful information and answers to the most important questions to keep your website running smoothly.

What are DoS attacks?

A DoS attack (Denial of Service) is a type of hacker attack where attackers try to make a resource, such as a website or server, inaccessible to other users. It looks like this: a resource starts receiving a huge number of requests that it simply cannot handle. Due to this overload, the system “hangs” and stops working normally.

Where did DoS attacks come from

The first cases of DoS attacks appeared in the late 1980s, when scientists began experimenting with so-called “worms” – programs that can independently spread through computer networks. In 1988, Cornell University student Robert Morris launched one of these worms, known as the Morris Worm. It infected thousands of computers across the Internet. Morris did not intend to organize a DoS attack, but due to the overload of infected systems, many users lost access to their devices.

Since then, DoS attacks have become much more sophisticated and have evolved into a tool for blackmail, sabotage, or even protests. With the spread of the Internet and the growing dependence on online services, these attacks are becoming an increasingly serious threat to both business and society as a whole.

Types of attacks

Denial of service (DoS) attacks are of different types, each of which acts in its own way:

• DDoS (Distributed Denial of Service) is the most common type of attack. Here, the attacker uses a network of infected devices, called a botnet, to create an excessive flow of traffic to the victim. Imagine thousands of computers controlled by a hacker sending requests to a website at the same time. The server can’t process so many requests and, simply put, “hangs” or stops responding.
  
• SYN attacks are aimed at overloading the server buffers responsible for the connection. The hacker sends fake SYN (Synchronization) requests, to which the server tries to respond, but does not receive a response.
  
• HTTP attacks use HTTP requests to load a web server, which causes it to work at its limit or stop functioning altogether.
• DNS attacks are a way to overload DNS servers that are responsible for resolving domain names to IP addresses, which leads to the inaccessibility of websites.

What is the difference between DoS and DDoS attacks?

While DoS and DDoS attacks are similar in result – they both cause a denial of service – their methods of implementation and goals are different.

DoS attacks:

• Source: an attacker launches an attack from one computer, sending a large volume of requests to the target server.
• Purpose: the main goal of such attacks is to temporarily disable the site to damage the company’s reputation or block access to its resources.
• Complexity: DoS attacks are easier to implement and require fewer resources than DDoS.

DDoS attacks:

• Source: An attacker uses a network of infected devices, known as a botnet, to send requests to a victim site in bulk.
• Purpose: DDoS attacks are often intended to extort money, exert political pressure, sabotage or destabilize a network.
  
• Complexity: Such attacks are much more difficult to execute, as they require large resources and specialized knowledge to manage a botnet.

Examples of DoS attacks

DoS attacks are not just something theoretical, but a real threat faced by both large companies and ordinary users around the world. Here are a few examples of such attacks that have occurred in recent years:

Global Windows outage in 2024

In July 2024, a large-scale failure of the Windows operating system occurred, affecting the work of airports, banks, and telecom operators in different countries. There are assumptions that this was caused by a problematic updated version released by Crowdstrike. Although there was no direct evidence of a DoS attack, many experts believe that the update could have been deliberately modified or used by attackers to cause this global outage.

It’s worth remembering that these cases are just a drop in the bucket of all the DoS attacks that take place in the world. With the development of technology, such attacks are becoming more complex and dangerous, so it is important to pay more attention to preventing and protecting against them.

Consequences of attacks for websites

• Site is down. The first thing users will notice is that the site is simply unavailable. As a result, the company loses customers, profits fall, and its image begins to limp.
  
• Data leakage. Hacker attacks can cause theft of data stored on the server, and this is a real disaster for business.
• Blow to reputation. Site failures will scare away customers, and the company may lose the trust of the audience. Deterioration of reputation is something that is difficult to fix later.
  
• Financial losses. Freezing of revenues due to the site being down, the cost of restoring it, and lost customers can all cost a business a tidy sum.
  
• Legal issues. In some cases, attacks, such as DoS, can have serious legal consequences. This is especially true for attacks on important infrastructure objects or systems.

How to ensure website stability

Protection against DoS attacks is a rather complicated task that requires the use of different approaches and technologies.

Ways to protect against DoS attacks:

1. Use special tools and equipment to filter malicious traffic coming from infected devices.
2. Set a limit on the number of requests from one IP address over a certain period of time to avoid overloading.
   
3. Connect a CDN (content delivery network) – a system with distributed servers that will help distribute the load during an attack by redirecting requests to other servers.
4. Use programs to monitor traffic and detect suspicious activity that may indicate the beginning of a DoS attack.
   
5. Apply temporary blocking of IP addresses from which malicious requests are coming.
   
6. Use specialized services that provide protection against DoS/DDoS attacks and help to improve security.
7. Regularly back up your data to be able to restore your website in case of a successful attack.

To ensure that your website remains secure, it is important to take a comprehensive approach and be prepared for different types of threats.

And finally…

Basic rules of protection against DoS attacks:

1. Continuous software updates to close holes in the system that can be penetrated by hackers.
2. Complex passwords make it much harder for unauthorized persons to access servers and systems.
3. It is important to train employees on the basics of cybersecurity and how to behave safely online.
4. Monitoring network traffic on a regular basis allows you to notice strange activity in time that may indicate a DoS attack attempt.
5. Two-factor authentication is an additional layer of protection for access to servers and systems, which makes it difficult to hack.

Conclusion

Don’t rely on only one method of protection. It is better to use different methods in combination. Also, don’t forget to regularly update your security methods, as attackers are constantly coming up with new tricks for attacks.