A distributed denial-of-service (DDoS) attack is one of the most destructive tools in the cybercriminals' arsenal. With more and more companies moving their business online, any disruption in the website's stability causes substantial financial losses.
A DDoS attack involves bombarding the website with traffic to put it out of service. The goal is to slow the target down or disable it entirely. Motivations of attackers differ from fun to financial gain to ideology.
How Does a DDoS Attack Work?
Since the goal of the attack is to generate a substantial amount of traffic, hackers need special tools to create it.
Botnets
An attacker sends malicious software to poorly protected computers. Usually, it comes in the form of a corrupt email or attachment. Over time, hackers create a network of infected computers, which is called a botnet.
When the time comes to attack, cybercriminals instruct and control the botnet's actions. They command numerous computers to flood a website with traffic. As unsuspecting invaders bombard the website with their presence, it goes offline.
Today, unprotected computers are only part of what hackers use to create a botnet. Many of them are taking full advantage of vulnerable IoT devices. It could be a security camera, a smart TV or even an air purifier.
The lack of regulatory control over smart devices makes them excellent weapons in cyberattackers' hands. If an IoT device has a unique IP address, it can become a part of a botnet.
Memcached Servers
An attacker can also overload a website with internet traffic by sending fake requests to a vulnerable Memcached server (caching system to optimize websites relying on external databases). The server, in turn, responds with a larger amount of data than the original request, thus amplifying the volume of traffic.
While the infrastructure is overloaded with incoming traffic, regular legitimate requests can't be processed.
A Memcached attack requires fewer resources than its botnet counterpart does. However, it involves searching for a vulnerable Memcached server, which isn't always available.
3 Forms of DDoS Attacks
Numerous types of DDoS attacks exist. They can be divided into three categories:
1. Volume-Based DDoS Attacks
The most common type of DDoS attack is volume-based. It involves a substantial number of requests sent to one target. The intention is to overwhelm the network capacity and bring the website or online service down.
2. Application-Based DDoS Attacks
To initiate an app-based DDoS attack, cybercriminals take advantage of vulnerabilities in the web server or application software to cause the web server to hang or crash.
The most common approach to an app-based attack is to send partial requests to the server to overload its database connection pool and prevent the acceptance of legitimate requests.
3. Protocol-Based DDoS Attacks
This type of attack exploits the Internet protocol and the weaknesses of its layers. While the server or any other network hardware is processing legitimate requests, the attack consumes its resources causing a disruption.
These attacks target your network stack by sending more packets than it can process or bigger bandwidth than a network port can handle.
The Worst DDoS Attacks in History
Let's take a look at the worst DDoS attacks in the planet's history.
1. GitHub
The worst DDoS attack to date took place in February 2018. Back then, an online code management service, GitHub, was hit with a Memcached DDoS attack. Even though the platform handled large volumes of traffic regularly, it couldn't deal with 1.35 terabits per second.
Since GitHub was well-prepared for the attack and used a DDoS protection service, the entire battle took less than 10 minutes so the company didn't suffer as many unfortunate consequences as the victim of the second-worst DDoS attack in history.
2. Dyn
The attack on Dyn, a major DNS provider, took place in October 2016. It disrupted the work of numerous websites, including those belonging to Amazon, Netflix, Twitter, Airbnb, Visa, and PayPal.
The hackers used a botnet of 100,000 IoT devices for the attack. Even though Dyn quenched the attack in one day, it still cost the company more than $110 million.
What are the First Signs of a DDoS Attack?
According to IT security experts from Firewall Technical, knowing the signs of a DDoS attack can help you avoid unfortunate consequences:
The website is loading and responding slowly.
The website is completely unresponsive.
Users report problems with accessing the website.
You are experiencing Internet connection issues.
You get numerous spam emails.
Remember, a DDoS attack is aimed at putting your website down, not stealing information. So your first actions should involve blocking the traffic and setting up virtual walls rather than protecting the data.
While it's possible to block a DDoS attack, the process is tough and not always effective. A much better solution is to prevent it from happening.
How to Prevent a DDoS Attack
What can you do to prevent a DDoS attack on your website? Lightsabers won't work. You need to bring in the heavy artillery.
1. Develop a Response Plan
When the first symptoms of the DDoS attack appear, you only have minutes to react. That's why you must have a response plan to follow.
All team members should know their responsibilities. Make sure you have a list of internal and external contacts that should be notified about the attack immediately.
2. Ensure Strong Security Practices
All your network security tools must be implemented and updated. Don't forget about strong passwords, anti-phishing methods, and efficient firewalls.
Website maintenance is a critical part of security measures. Ensuring your website's safety and stability can help you prevent cyberattacks and react to threats timely.
3. Take Advantage of Different Servers
Strong network architecture can help minimize losses. If hackers attack one server, the other can handle vital network traffic. Ideally, servers should have different geographical locations.
4. Use Anti-DDoS Software
While such software won't protect against all types of DDoS attacks, it can beef up your security measures. These tools can monitor all incoming traffic to detect and block an attack when possible.
Be Ready for a DDoS Attack at All Times
You don't have to be a powerful enterprise to become a victim of a DDoS attack. Hackers may decide to use your website for target practice. That's why you should always be prepared.
Take full advantage of anti-DDoS tools and pay extra attention to website maintenance.
