Flood attack: prevention and protection

In today's digital age, security breaches and cyber-attacks are becoming more and more common. One such form of attack is “flood attack”. Such attacks can disrupt services, make websites unavailable, and disrupt the overall operation of networks. In this blog post, we'll take an in-depth look at what a flood attack is, why it's dangerous, how to defend against it, and the different types.

What is a flood attack?

A flooding attack, often a form of Distributed Denial of Service (DDoS) attack, aims to overwhelm the system with unnecessary requests, thus preventing legitimate requests from being fulfilled. The main goal is to make the target service unavailable by consuming all its resources or completely destroying it. Flooding attacks take advantage of network bandwidth, memory, and processing power limitations. By sending an excessive number of requests, they can quickly exhaust these resources and cause serious disruptions. Attackers often use botnets, networks of compromised devices, to generate the huge traffic volumes required for such attacks, making it difficult to track and block sources.

How does this work?

A flooding attack works by sending a large volume of traffic to a targeted server, service, or network. This traffic often comes from legitimate users, making it difficult to distinguish and filter. The target system suffers from this increase in requests, eventually causing it to crash or shut down. Flooding attacks can be carried out through a variety of protocols and methods, such as TCP, UDP, ICMP, and HTTP, each of which exploits different aspects of the network's communication process. Advanced flooding attacks can use randomization techniques to evade detection and mitigation efforts, making them more complex and difficult to prevent.

Why is flood attack dangerous?

• Violation of Service: The most immediate impact is service disruption. Websites may be unavailable, networks may slow down, and businesses may experience interruptions.
• Financial implications: With overtime comes lost income. Especially for businesses that rely heavily on online services, a few minutes of unavailability can translate into significant financial losses.
• Damage to reputation: Continuous attacks can damage a company's reputation and lose customer trust and loyalty.
• Resource consumption: To manage the consequences of such attacks, a large amount of resources, both human and technological, need to be directed.
• Diversion: Sometimes attackers use flood attacks as a smokescreen to distract from a more stealthy breach or intrusion.

How to soften it?

• Monitoring: Continuous monitoring of network traffic can help early detection of unusual traffic spikes that may indicate a flood attack. Tools like intrusion detection systems (IDS) can be invaluable.
• DDoS protection: DDoS protection services can help mitigate the effects of a flood attack. These services often use a combination of traffic filtering, rate limiting, and other tactics to ensure that only legitimate traffic reaches the destination.
• Secondary DNS: If the primary DNS server is overwhelmed by a flooding attack, the secondary DNS server can continue to resolve domain names, ensuring that services are available to legitimate users.
• Firewalls and routers: Properly configured firewalls and routers can help filter malicious traffic.
  Router and firewall
• TTL analysis: Examine TTL values ​​in incoming packets. Abnormal TTLs can indicate potentially malicious traffic.
• IP block list: Identify and block malicious IPs. This prevents them from accessing your systems further.
  Blacklist vs. Whitelist

Types of flood attacks

DNS Flood Attack

A DNS flood attack specifically targets Domain Name System (DNS) servers. DNS is the Internet's phone book and translates human-friendly URLs (such as “example.com“) to the IP addresses that computers use to identify each other on the network (for example, “1.2.3.4“). In a DNS flooding attack, attackers typically send a high volume of DNS lookup requests using spoofed IP addresses. This causes the DNS servers to try and resolve each query, resulting in a large number of processes. This congestion ensures that genuine requests from real users are either significantly delayed or ignored altogether. If an attacker successfully compromises a DNS server, it can make entire websites or online services unavailable.

SYN flood attack

To understand a SYN flood attack, one must first understand the “three-way handshake” process used to establish a TCP connection. The sequence is SYN, SYN-ACK and ACK. In a SYN flood attack, an attacker sends a rapid succession of SYN requests, but either does not respond to SYN-ACK responses, or sends them from spoofed IP addresses. The target system will keep these connections open, waiting for the final ACK, which never arrives. This can consume all available slots for new connections, effectively shutting down legitimate users.

HTTP Flood Attack

HTTP flood attacks use the HTTP protocol that web services run on. In this attack, a large number of HTTP requests are sent to an application. Unlike other flooding attacks, the traffic sent looks legitimate. Requests can be mixed with either valid URL routes or invalid ones, making them difficult to detect. Requests are particularly difficult to filter because they closely resemble typical user traffic. This method can consume server resources and cause legitimate requests to time out or receive delayed responses.

ICMP (Ping) Flood Attack

ICMP, or Internet Control Message Protocol, is a network protocol used by network devices to send error messages. The Ping tool uses ICMP to check the availability of network hosts. In a ping flood attack, attackers flood the target with ICMP Echo Request (or 'ping') packets. The target then tries to respond to each of these requests with an echo response. If the attack is large enough, the bandwidth or processing capabilities of the target system may be overwhelmed, causing a denial of service.

Suggested page: ICMP Ping monitoring function

UDP Flooding

User Datagram Protocol (UDP) is a sessionless network protocol. In a UDP flooding attack, an attacker sends multiple UDP packets, often with spoofed sender information, to random ports on the victim's system. The victim's system will try to find the software associated with these packages, but will not be able to find any. As a result, the system will often respond with an ICMP 'Destination Unreachable' packet. This process can saturate the system's resources and bandwidth, preventing it from processing legitimate requests.

Impact of flood attacks on various industries

Flood attacks can have devastating effects on a variety of industries, each with unique challenges and potential damages:

E-commerce:

E-commerce platforms rely heavily on their website for sales and customer interaction. A flood attack can cause significant disruption, leading to lost sales, reduced customer confidence, and potentially long-term damage to brand reputation. In addition, the costs associated with reducing attack and strengthening security measures can be significant.

Offer: Global Reach, Local Touch: The Role of GeoDNS in Expanding E-Commerce

Finance:

In the financial sector, the availability and integrity of online services is of critical importance. Flood attacks can disrupt online banking, trading platforms and payment processing systems. Not only does this affect customer operations, but it can also lead to compliance issues and regulatory audits. Financial losses and the impact on customer confidence can be severe.

Healthcare:

Healthcare providers use online systems for patient management, medical records, and telemedicine. A flood attack can disrupt these services and potentially put patient health at risk. Late access to medical records and appointment scheduling can cause significant operational disruptions and affect the quality of care provided.

Game:

The gaming industry is often the target of flood attacks, especially during major events or game launches. These attacks can break the game, cause frustration among users, and result in lost revenue for game companies. The competitive nature of online gaming also means that downtime can have a significant impact on player engagement and retention.

The result

Flood attacks are one of the oldest tools in a hacker's arsenal, but they remain effective. As the digital landscape grows and evolves, so do the methods used by attackers. Regularly updating your security infrastructure, being aware of emerging threats, and using a proactive defense strategy can go a long way in keeping systems secure and up and running.

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Tags: DDoS Attack, DDoS Protection, DNS, DNS Flood Attack, Flood attack, HTTP Flood Attack, ICMP, ICMP (Ping) Flood Attack, monitoring, secondary DNS, SYN Flood Attack, TCP, TTL, UDP Last modified: July 23, 2024