Everything you need to know about denial of service attacks

After reading this article, you will be able to better understand:

• What a denial of service attack is and how it works
• What is a botnet?
• What are the motivations behind a denial of service attack?
• How to protect yourself from a denial of service attack

A full bus

You're at the bus stop during rush hour. A bus arrives; it's full, and no one's getting off. So you can't get on. Five minutes later, it's the same story. While people are piling up at the station, you decide to go one stop further, hoping that seats will become available, which unfortunately doesn't happen.

You then learn that the entire transportation network is paralyzed by people who remain in vehicles and refuse to get out, preventing citizens from using them. While far-fetched, this analogy accurately represents a denial-of-service cyberattack .

What is a denial of service attack?

A denial of service attack, derived from the term DoS ( denial of service), is a cyberattack that aims to disrupt the regular traffic of any service, network or server by attempting to overwhelm it with an extreme flood of internet traffic.

Today, the majority of denial of service attacks are distributed denial of service attacks, or DDoS attacks .

How does a denial of service attack work?

To carry out a denial-of-service attack, a hacker must have an army of bots, also called zombies. Bots are computers, phones, or any other internet-connected devices infected with the same malware that allows the hacker to control the group remotely. The collection of devices forms an army of thousands or even millions of devices called a botnet.

The cybercriminal then asks each machine in his army to make a request to the target's IP address in order to overload it and disable it. This results in a denial of service for the target's normal traffic, such as a website. This is our original bus.

Make no mistake, although this operation may seem like it requires a mastery of various IT solutions, it is relatively simple to purchase a botnet on the internet for the modest sum of $150. Given that SMEs are the most targeted by cyberattacks, it is important for them to take all possible precautions to protect themselves against these cyberattacks.

How are botnets created?

Botnets are deployed by bot propagators who, most often, infect various devices via a Trojan horse. Typically, the user will become infected by opening an email attachment, clicking on a malicious pop-up, or downloading compromised software from a website.

Once they spread, botnets have free access to data on the devices they reside on. They can modify it or even attack other computers. This is why it's important to protect yourself by developing good internal IT security practices .

Furthermore, as more and more of our devices are connected to the internet, what we call the IoT (Internet of Things), the cybersecurity issues associated with the many technological tools that we use become crucial.

What are the motivations behind a denial of service attack?

There are many motives for denial-of-service attacks. Some cybercriminals want to take over a company's website in order to disrupt its business operations and extract a ransom.

Other so-called "committed" cyber hackers, also called hacktivists, may take over the computer network of an international organization or a government in order to convey a political message.

DDoS attacks have even been used to distract an organization's system administrators, allowing hackers to plant malware on their victims.

How do I know if I'm the victim of a denial of service attack?

According to Norton , a cybersecurity solutions provider, the symptoms of a denial of service attack include:

• Slow file access, locally or remotely
• Long-term inability to access a particular website
• Inability to connect to the internet
• Inability to access all websites
• Receiving a large amount of phishing emails.

How to protect yourself against denial of service attacks?

Businesses should not underestimate the power of a DDoS attack; there are several methods that can help you counter them. It is very important to have a combination of technological solutions and internal processes that will allow you to protect yourself.

First, you need on-site monitoring tools that are active 24/7. Then, you need a team of experts who can respond to any type of attack. Finally, you need a cloud infrastructure to redirect the malicious traffic generated by the botnet.

Protecting yourself against denial of service attacks in six steps

A10 , another cybersecurity solutions provider, offers a six-step process that will allow you to effectively defend against DDoS attacks.

1. Your on-site tools automatically detect the attack and activate the mitigation process
2. Your team of experts is automatically alerted when the attack reaches a point of no return and cannot be countered by the equipment in place
3. The team then verifies that it is a real attack; it could be a false alarm. It analyzes the attack, proposes mitigation solutions and activates the relay of requests to the cloud if the need arises
4. A diversion signal is sent to the cloud along with details of the attack
5. The cloud team diverts traffic for analysis, using Border Gateway Protocol (BGP) or Domain Name System (DNS)
6. When the attack is over, traffic is restored to its usual path through the ISP

Nexxo can help protect you against denial of service attacks

With many years of experience in IT management for Quebec companies in various industries, Nexxo can help strengthen your IT infrastructure. We offer real-time monitoring and various security tools to protect you at all times. Do you have any questions? Don't hesitate to contact us directly by email or phone.