Our digital world relies heavily on the seamless functioning of online platforms. Unfortunately, with this connectivity comes the looming, always-evolving, and never-ending threat of cyber attacks. One such menace that has gained particular notoriety and is only picking up in both frequency and intensity is the distributed denial-of-service (DDoS) attack.
In this article, we’ll take a deep dive into the world of DDoS attacks, exploring what they are, how they work, the various types, and most importantly, how to protect your company from their disruptive onslaught and interference with service availability.
What is a DDoS Attack?
At its core, a DDoS attack is like an overwhelming digital traffic jam. Imagine trying to enter a building, but instead of a steady stream of people, you’re faced with an avalanche of individuals all attempting to enter at the same time. The same happens in a DDoS attack, only the people are digital traffic and the building is a website. In a DDoS attack, the attackers use multiple compromised devices to flood a target system or network with traffic, rendering it temporarily or indefinitely unavailable, meaning your end users can no longer access your site or service, and you lose money.
How do DDoS Attacks Work?
The best way to think of how a DDoS attack works is a busy telephone signal. It’s extremely frustrating to get one, but you’re only getting one because of the overwhelming demand for the service you are trying to access.
In a similar vein, a DDoS attack overwhelms a target server or network by flooding it with an excessive volume of requests. These requests could be in the form of data packets, HTTP requests, or even connection requests. The sheer volume of incoming traffic exhausts the target’s resources, leading to a breakdown in service.
The cyber criminals who carry out DDoS attacks use networks of Internet-connected devices that they’ve infected with malware that allows them to control the devicee remotely. These infected devices are known as bots (or zombies), and a group of bots forms a botnet. Once they’ve established a botnet, the attackers can direct an attack by sending remote instructions to each bot. Each bot sends requests to the target’s IP address, causing the server or network to become overwhelmed and resulting in a denial-of-service to normal traffic.
How To Spot a DDoS Attack
The early spotting of DDoS attacks is extremely important for implementing timely mitigation strategies. The earlier you spot an attack, the less damage it will do – not just to your service but also to your customers’ sites and applications.
Here are the signs and signals that your website may be under a DDoS attack:
1. Unusual Traffic Patterns
DDoS attacks often result in a significant increase in incoming traffic that can overwhelm your servers. Monitor your network traffic regularly and be vigilant for sudden spikes or unusual patterns.
2. Increased Network Latency
A sudden increase in response times or delays in accessing your services may indicate a DDoS attack, especially if it is affecting the performance of your website or applications. Be sure to measure network latency regularly.
3. Service Disruptions
Keep an eye on your online services for unexpected disruptions or outages. If users report difficulties accessing your website or services, investigate promptly.
4. Unusual Server Resource Utilization
A DDoS attack can cause a surge in resource consumption as your servers attempt to handle the increased traffic. Monitor the utilization of server resources such as CPU, memory, and bandwidth.
5. Anomalous Request Patterns
DDoS attacks often involve a large number of requests from a limited number of sources.
Look for irregularities such as an unusually high number of requests from a single IP address or a specific set of IP addresses.
6. Unexplained Network Traffic
DDoS attacks can involve a variety of protocols, so be attentive to abnormalities in different types of traffic and review your network logs for any unexplained or unexpected traffic.
7. Distributed Traffic from Multiple Locations
DDoS attacks are often distributed, meaning the malicious traffic comes from multiple sources. If you notice a widespread impact across different geographical locations, it may be indicative of a DDoS attack.
8. User Complaints
Users on the front lines may notice issues before automated monitoring systems do. Pay attention to user complaints or reports of slow performance or unavailability. Customer-submitted service tickets suck up valuable resources and time, ultimately leading to a poorer button line.
Types of DDoS Attacks
DDoS attacks come in various shapes and sizes and are always evolving as tech evolves.
Currently, the main types of DDoS attacks are:
1. Volumetric Attacks
Volumetric attacks flood a target’s network with a massive volume of traffic, overwhelming its bandwidth and causing service disruption. Common volumetric DDoS attack types include SYN flood attacks, ICMP flood attacks, and UDP flood attacks.
2. TCP State-Exhaustion Attacks
TCP state-exhaustion attacks exploit the limitations of the TCP protocol by exhausting the available connection state table entries on servers, rendering them unable to handle new legitimate connections. Examples include SYN/ACK flood, ACK Flood, and TCP connection exhaustion attacks.
3. Application Layer Attacks
Also known as layer 7 (L7) attacks, application layer attacks target the application layer and seek to exploiting vulnerabilities in the software or applications running on the server, causing a slowdown or complete service disruption. Examples include HTTP/HTTPS flood and slowloris attacks.
4. Protocol-Based Attacks
These attacks exploit vulnerabilities in the protocols used for communication between servers, consuming server resources and leading to service degradation. Examples include Ping of death, smurf attacks, and NTP amplification attacks.
5. Reflection Amplification Attacks
Reflection amplification attacks combine two popular attack methods: reflection and amplification. In reflection attacks, the attackers spoof a target’s IP address and send a request for information, usually via the User Datagram Protocol (UDP) or sometimes the Transmission Control Protocol (TCP). Amplification attacks generate a high volume of packets to overwhelm the target website without alerting the intermediary. The attack is triggered when a vulnerable service responds with a large reply when the attacker sends the request. A reflection/amplification attack combines the two, allowing attackers to both magnify the amount of malicious traffic they can generate and obscure the sources of the attack traffic.
6. Spoofed Packet Attacks
In spoofed packet attacks, the attackers send packets with falsified source IP addresses, making it challenging to trace the origin and overwhelming the target’s infrastructure.
7. Ransom DDoS Attacks
An increasingly common DDoS attack type is ransom DDoS attacks, where the attacker sets up the attack but then demands money from the attack target in exchange for not carrying it out.
Understanding these main types of DDoS attacks is essential for developing effective DDoS mitigation strategies and safeguarding against potential threats. It’s also worth noting that attackers often use a combination of these techniques to create more potent and sophisticated DDoS campaigns.
How To Protect against a DDoS Attack
There are various ways to protect against a DDoS attack, including
1. Content Delivery Networks (CDNs)
Leverage content delivery networks to distribute your website’s content across multiple servers and locations. CDNs can absorb and distribute traffic, minimizing the impact of DDoS attacks on a single server.
2. Traffic Monitoring and Anomaly Detection
Implement robust traffic monitoring and anomaly detection systems. By establishing a baseline of normal traffic behavior, you can quickly identify any deviations or anomalies to mitigate an attack.
3. Rate Limiting
Set up rate limiting on your network devices to restrict the number of requests from a single source within a specified timeframe. This can help prevent overwhelming your servers with excessive traffic.
4. Load Balancing
Use load balancers to distribute incoming traffic across multiple servers. This not only improves the overall performance of your system but also ensures that no single server becomes a bottleneck during a DDoS attack.
5. Cloud-based Services
Consider migrating your services to cloud-based platforms that offer scalable infrastructure. Cloud providers often have DDoS protection mechanisms in place and can absorb large volumes of traffic. A hybrid setup – where you have cloud-based back-up of on-premises protection service– is another option.
6. Incident Response Plans
Develop a comprehensive incident response plan that outlines specific steps to take in the event of a DDoS attack. Assign roles and responsibilities to your team members to ensure a coordinated and swift response.
7. IP Blacklisting/Whitelisting
Maintain a list of known malicious IP addresses and use IP blacklisting to block traffic from these sources. Conversely, consider IP whitelisting to only allow traffic from trusted sources.
8. Regularly Update and Patch Systems
This is of course a general IT best practice, but DDoS attackers often exploit vulnerabilities in outdated software, so staying current is crucial. Be sure to regularly update and patch all systems and software.
9. Training
Establishing an effective in-house or third-party provided training program that ensures your employees receive continuing DDoS education is an essential part of DDoS protection. If your employees aren’t in the know, it increases the likelihood of a DDoS attack and leaves your company more vulnerable to one.
10. Implement DDoS Protection Services
Finally, the best you can do to mitigate DDoS attacks is proactively protect yourself against them by Investing in a dedicated DDoS protection service such as Corero. These services often employ advanced traffic filtering and mitigation techniques to identify and block malicious traffic while allowing legitimate traffic to reach your servers.
Conclusion
As our reliance on digital platforms continues to grow, so does the importance of safeguarding against cyber threats like DDoS attacks. Understanding their nature, mechanisms, and defense strategies is extremely important for organizations and individuals alike. Having a robust DDoS solution in place allows you to ensure that customers, clients, and good traffic can still reach your website even in the event of an attack. Learn how Corero helps you do this by clicking here.