- DDoS attacks overwhelm target systems with fake traffic, causing service interruptions and potential financial losses.
- Attackers create botnets by infecting devices, giving remote commands, and launching various types of attacks.
- To prevent DDoS attacks, it is feasible to use third-party protection tools, work closely with ISPs, monitor traffic patterns, implement load balancing, and regularly update network equipment and software.
A Distributed Denial of Service (DDoS) attack is orchestrated to disrupt a website, computer, or online service by overwhelming it with a high volume of requests, effectively incapacitating its ability to handle legitimate traffic.
1. Basic principles of DDoS
The basic principle of a DDoS attack is to overload the resources of a target system, service, or network so that it cannot properly respond to requests from legitimate users. This type of attack usually involves a large number of computers or devices that are manipulated into a large “botnet”. Attackers use this vast network to work together to launch large-scale attacks against a target, causing it to become overwhelmed.
A DDoS attack can be likened to a traffic jam in the cyber world, in which the attacker sends out fake requests as if blocking the main road, making it impossible for legitimate traffic to enter from the feeder. Such denial-of-service attacks not only compromise service availability, but can also lead to business interruptions, data breaches, and financial losses.
Also read: Surge in ransomware attacks: Reasons and repercussions
2. How does a DDoS attack work?
DDoS attacks are powerful and destructive because they take advantage of a large number of computers or devices, organising them into a vast network that works in concert to launch an attack on a target.
Turning devices into botnets
Attackers infect a large number of computers, servers or IoT devices by various means to turn them into botnets. This is usually achieved through malware, viruses or other attacks. These infected devices are remotely controlled and become part of the attacker.
Creating a botnet
Once the devices are infected, the attacker organises them into a vast network, often referred to as a botnet or botnet. each infected device in this network can perform tasks specified by the attacker, and this is usually done by launching simultaneous attacks against specific targets.
Remote command and control
An attacker remotely manipulates a botnet through a remote command and control (C&C) server. These commands may include launching DDoS attacks, changing attack strategies, or switching targets. The attacker can adjust the strength and method of the attack at any time.
Launching network attacks
Once the attacker gives an order, the devices in the botnet start launching cyber attacks against specific targets. The attack can be of various methods and types, including UDP Flood, TCP/IP Exhaustion, ICMP Echo Request, HTTP Flood, SYN/ACK Flood, etc.
Crashing the service
A large number of fake requests and malicious traffic flooding the target system at the same time exceeds its processing capacity, causing the service to crash or become extremely slow. This can prevent legitimate users from accessing the target’s network services properly, resulting in the unavailability of services.
Persistent attacks
DDoS attacks usually last for a long period of time and can last for hours or even days. Attackers often take steps to make attacks difficult to track, such as by using proxy servers, manipulating source IP addresses, and other means to make defence more difficult.
Also read: Things to know about the dangers of ransomware attacks
3. Types of DDoS attacks
There are several types of DDoS attacks, categorised into three main groups: volumetric attacks, protocol attacks, and application layer attacks.
Volumetric attack
A volumetric attack inundates the network layer with seemingly genuine traffic, leading to network congestion. This is the most prevalent type of DDoS attack. An instance of a volumetric attack is DNS amplification, where open DNS servers are exploited to bombard a target with DNS response data.
Protocol attack
A protocol attack disrupts services by exploiting vulnerabilities in the layer 3 and layer 4 protocol stack. One common example is a SYN flood attack, overwhelming server resources by inundating them with synchronisation requests.
Resource layer attack
A resource (or application) layer attack focuses on web application packets, disrupting data transmission between hosts. Examples include HTTP protocol violations, SQL injection, cross-site scripting, and other layer 7 attacks.
Cyber attackers may deploy multiple attack types, combining or transitioning from one to another to cause significant harm to a system.
4. How to prevent DDoS attacks?
Use third-party DDoS protection tools
Many cloud service providers and specialised DDoS protection service companies offer powerful DDoS protection tools. These tools can help identify and mitigate DDoS attacks, ensuring that normal traffic continues to access your network and services. Choose a trusted third-party service to ensure it can effectively accommodate different types and sizes of attacks. Test DDoS protection programs regularly to ensure their effectiveness and reliability.
Work with ISP
Work with internet service provider (ISP) to develop a DDoS protection strategy for “clean” bandwidth; ISPs often have systems in place that can detect and filter malicious traffic, blocking attacks before they reach an organisation’s internal network. Establishing a close working relationship ensures that the ISP’s DDoS protection measures are updated and adapted to new threats.
Traffic monitoring tools
Use traffic monitoring tools to regularly examine network traffic patterns for early identification of DDoS attacks. This can include monitoring for unusual traffic spikes, unusual request frequencies, etc. Configure traffic monitoring tools to generate alerts or trigger automated defence mechanisms. The monitoring system needs to be able to recognise the difference between normal and abnormal traffic.
Load balancing
Use load-balancing techniques to spread traffic and ensure that all servers share the load equally. This helps to mitigate the impact of DDoS attacks, as attack traffic cannot be centralised on a single server. Configure the load balancer to adapt to changes in network traffic and ensure that it does not become an attack target itself.
Update equipment and software
Update network equipment and software in a timely manner to patch known security vulnerabilities. Strengthening your network security infrastructure can reduce the risk of a DDoS attack.
A combination of these measures can greatly improve an organisation’s ability to withstand DDoS attacks and protect the stability and availability of the network.
