12/13 2023

What is a DDoS Attack? How to Safeguard Against Them?

The incidents of cyberattacks are rampant. Cloudflare, AWS, and Google earlier detected large-scale network attack activities simultaneously. Analysis of the attacks indicates that this assault can generate significantly massive traffic using fewer zombie computers, nearly three times higher than the DDoS attack records previously intercepted by Cloudflare! Corporate cybersecurity is currently in a high-risk state. Confronted with ever-evolving cyber threats like ransomware or malicious software attacks demanding payment in cryptocurrency form, without a robust cybersecurity plan in place, the consequences could involve data breaches, system paralysis, and more. In this era of advanced technology, understanding the various attack methods is crucial for enterprises. Let Nextlink take you through it all in one go!

What is DDoS Attack?

Imagine a scenario where a restaurant during its evening dining hours is already unable to accommodate any more customers. Suddenly, more than 10 groups of customers rush in, eager to dine at the restaurant. Undoubtedly, the manager and staff would struggle under this sudden surge, unable to handle the load, resulting in an inability to provide optimal service and potentially slowing down the entire process.

DDoS Attack is Similar~

DDoS, short for Distributed Denial of Service Attack, aims to disrupt the normal functioning of a target website, server, or network service, thereby preventing legitimate users from accessing the service. This type of attack often involves a large number of computers or zombie machines coordinated by hackers to inundate the target server or website with an enormous volume of network traffic requests. This overload causes service interruption, resulting in damage to the operations of the affected entity.

Even major corporations fall victim to DDoS attacks. In June 2023, global tech giant Microsoft issued a statement acknowledging service disruptions within Microsoft 365 office software, including Outlook and Teams. These disruptions lasted over two hours initially, followed by a prolonged half-day interruption, impacting tens of thousands of users. Additionally, Azure cloud platform’s Virtual Private Servers (VPS), equivalent to AWS EC2, also experienced service interruptions due to a surge in service traffic. This demonstrates that cyberattacks transcend borders and affect entities of all scales, underscoring their ongoing nature.

How do DDoS attacks work?

DDoS attacks possess four characteristics, as evidenced by the example of Microsoft Azure being attacked by hackers:

Distributed Attack Source:

Cyber attackers typically employ a multitude of infected devices or zombie computers to launch attacks. These devices are often spread globally, allowing attackers remote control to inundate the target computers with massive traffic or requests.

High Traffic:

DDoS attacks typically involve substantial traffic ranging from tens of megabits to hundreds of gigabits that can simultaneously assault a single system. Such high traffic overwhelms the target system’s bandwidth and processing capacity, rendering it unable to function properly.

Multiple Attack Vectors:

Additionally, DDoS attacks utilize different attack vectors, including SYN flooding, where a vast number of incomplete Transmission Control Protocol (TCP) connection requests are sent to the target system; UDP flood attacks, sending a large volume of User Datagram Protocol (UDP) packets to overload the system’s processing capacity; or HTTP flood attacks, simulating normal HTTP requests but overwhelming the server with an excessive number of connections and requests.

Attack Length and Duration:

Attackers can choose the duration of their attacks based on their objectives, ultimately aiming to cripple a company’s systems and significantly impact its business operations over an extended period.

How can organizations establish DDoS attack prevention strategies to ensure robust security?

DDoS 攻擊來勢洶洶 如何強化安全性?
DDoS attacks are a quite common method and also one of the most easily overlooked details by businesses.

How to protect against DDoS attacks?

Faced with ever-evolving attack methods and considering that DDoS attacks directly impact many enterprise production systems, protective strategies become the top priority in fortifying cybersecurity:

Traffic Analysis and Monitoring:

When deploying DDoS attack protection, real-time traffic monitoring allows for rapid detection of abnormal traffic patterns. Simultaneously using network traffic analysis tools enables the identification of DDoS attack characteristics, such as a single IP address sending a vast number of requests, leaving malicious traffic with nowhere to hide.

Firewall and Intrusion Detection Systems (IDS/IPS):

Optimizing firewall settings is crucial. Firewalls act as well-secured locks at the entrance, restricting unnecessary traffic from entering the enterprise production environment and causing damage due to malicious traffic attacks. Additionally, Intrusion Detection and Prevention Systems (IDS/IPS) aid in detecting and filtering suspicious traffic.

Employing Load Balancers:

DDoS attacks target single servers or systems with high traffic assaults. Therefore, installing load balancers helps distribute traffic across multiple servers, preventing overwhelming a single server. Load balancers not only assist in detecting and blocking abnormal traffic but also ensure that systems affected by DDoS attacks still receive some traffic, maintaining user experience.

Capacity Planning and Backup Preparedness:

Within the realm of cybersecurity, designing adequate bandwidth and server resources to handle unexpected traffic peaks is crucial to maintain system stability. Moreover, regular data backups help prevent the loss of important data during a DDoS attack, avoiding irreparable situations.

What DDoS Protection Solutions does AWS Offer?

Traditionally, designing related resources in an on-premises environment poses significant challenges for small and medium-sized enterprises, especially in terms of equipment configuration, as retaining too many resources can lead to cost burdens. Hence, the flexibility and security advantages in a public cloud environment offer users optimal protection. From what we’ve seen, both “websites” and “SaaS software” are the systems most susceptible to DDoS attacks. How can one leverage the power of the public cloud to protect against DDoS attacks? AWS provides comprehensive solutions that enable enterprises to design simple and flexible DDoS protection frameworks for web applications.

By leveraging AWS architecture design, it provides protection for enterprises against DDoS attacks.

From the diagram, it’s evident that AWS Shield is AWS’s native DDoS protection service, offering automatic detection of common network attacks for free. In this architecture, AWS Shield Advanced is used, providing advanced protection and attack visibility by assessing traffic suspicion levels from the Network Access Control List (NACL), allowing closer proximity to the attack source and immediate blockage when necessary. Additionally, Amazon Route 53, a domain name system (DNS) service, assists in managing domain resolution, safeguarding against DNS application layer attacks. It’s complemented by Amazon CloudFront and ELB load balancing to assist in preventing DDoS attacks, effectively distributing traffic for balance.

Nextlink has achieved AWS Security Competency and holds extensive expertise in aiding clients with cloud migration and security implementation. Reach out to learn more about our robust cloud security solutions, including defense against DDoS attacks!