What Is a DDoS Attack? Definition, Types & More

Staving off DDoS attacks is always at the top of IT security pros' to-do lists. These attacks leverage large numbers and small timeframes to do damage to organizations' networks and reputations. They can cause serious downtime and, in some cases, bring entire operations to a standstill.

This article will help you mitigate the dangers DDoS attacks pose by first understanding how they work and then adopting the right techniques to keep them at bay.

What Is a DDoS Attack?

DoS stands for "denial of service," and it is a type of cyberattack in which a large amount of traffic is directed to a specific server or endpoint on a network in an attempt to overwhelm it. Once overwhelmed, the target system becomes unresponsive, denying service to anyone who attempts to reach it. DDoS attacks are simply a 'distributed' version of this in which many devices are used to attack at once.

Despite DDoS attacks generally not lasting longer than an hour at a time, their capacity for disrupting normal service accessibility is extreme, especially when attacks are repeated on a regular basis. This article will help you navigate the various types of DDoS attacks and strengthen your current DDoS defense strategy.

Three Common Types of DDoS Attacks

Although all DDoS attacks share the same characteristics — attempting to overwhelm network devices and doing so with an army of machines — they can be grouped by the type of resource they are leveraged against.

The following DDoS attack categories are the most common administrators and security pros tend to encounter:

Application Resource Overload

This type of attack effectively overloads the target system's memory and processing power. Inherent vulnerabilities in the software on a given server or device on your network are targeted by these types of attacks, leading to issues like memory leakage and high processing loads.

In some cases, the underlying data an application uses may be altered instead, achieving the same effect. This approach reduces the number of devices needed to bring down a given service, simplifying things for the attacker.

Network Resource Overload

When this kind of attack is underway, bandwidth and network devices are the primary vulnerabilities being targeted. Attackers may attempt to occupy all available bandwidth with bad requests or overload specific network devices.

Protocol Resource Overload

These DDoS attacks target connections and sessions, specifically. Keeping a large number of useless sessions alive is an example of this approach.

DDoS attacks can also be categorized by whether or not they use certain techniques. These categories include:

Standard Attacks

Standard DDoS attacks happen whenever a large amount of traffic is intentionally directed at a specific server or network device in an attempt to overwhelm it. However, there are a few ways that attackers have evolved their tactics beyond this traditional approach.

Attacks Using Reflection

DDoS attacks that use reflection leverage normal public servers to overwhelm target machines. This is done by simply spoofing the target machine's IP address in a request, leading the third-party public server to respond to the target instead of the attacker. This attack can be super effective on its own, but it is often paired with amplification techniques to make it more devastating.

Attacks Using Amplification

Amplification in the context of a DDoS attack occurs when an attacker finds a way to send a large payload of data to a target machine while only having sent a small payload from their own device.

A simple example of this would be an attacker spoofing their target's IP address to perform a reflection attack and requesting a large amount of data from a public server. The request they send is small, but the response sent by the public server to the target is much larger.

Best Practices for Defending Against DDoS Attacks

Defending against DDoS attacks is especially important for organizations that depend on their network services being available at all times. Here are a few best practices to adopt in order to keep your own systems secure from DDoS attempts:

Consider DDoS Attacks as Potential Diversions

Cyber attackers can use a DDoS attack to distract people from more serious actions, like stealing confidential data or injecting harmful software into your network. When dealing with a DDoS attack, try not to focus only on stopping the attack. You should recognize it as an indicator of compromise (IOC) and be aware of any other security problems that could be happening.

Manage and Monitor All Network Access Points

Even as your network grows and the number of endpoints it includes increases, you should have a good understanding of its general topology. Prioritizing mission-critical operations by providing surplus infrastructure in key areas can help to mitigate any potential DDoS disruptions.

Protect Against the Most Common DDoS Variants

Not all DDoS attacks are the same. As was discussed above, attacks differ by the type of resource being targeted. Protocol resource overload attacks focusing on transmission control protocol (TCP), user datagram protocol (UDP), and packet anomaly attacks were the most common DDoS variants used by cybercriminals in 2022. Protecting against these kinds of threats first and foremost can dramatically reduce your risk of suffering from a successful DDoS attempt.