What is a DDoS Attack? Understanding Flood-Based Cyber Threats

Flood-based cyber attacks have multiplied rapidly lately. These attacks usually target websites, applications, and systems, overwhelming the traffic, leading to disruptions. Popularly known as DDoS attacks (Distributed Denial of Service attacks), they can damage the servers, leading to huge financial losses. 

Before opting for measures to safeguard against denial of service attacks, it is important to know in-depth information about them. In this blog, we will discuss the rise of flood-based DDoS attacks, how they work, and their effects on digital platforms, helping you recognize and prepare for this growing cyber threat.

What is a DDoS Attack?

A distributed denial-of-service (DDoS) attack is a cybercrime in which the attackers disrupt the normal traffic of a site by flooding it with malicious traffic. Due to this, the target site crashes and cannot be accessed by the legitimate users. The disruption in services often leads to monetary backlash and reputation damage.

You must not confuse DDoS with DoS. In a Denial of Service (DoS) attack, the target site is flooded with a single source, whereas in a DDoS attack, multiple sources are used to flood the site with malicious traffic. This is the main reason why distributed denial of service attacks are more threatening and cause hefty damages. 

To carry out the attack, attackers use many infected computers known as botnets. Using them, they send huge amounts of data in one go. The main goal of a denial of service attack is to cause problems for a business or distract its security team while other attacks happen.

How Does a DDoS Attack Work?

Botnets are the main component involved in DDoS attacks. These are a network of hijacked computers used to overwhelm the target website with malicious traffic. They are controlled remotely by hackers, allowing them to send a huge amount of data requests in one go. The rapid increase in website traffic crushes its services, leading to the slowing down of websites or complete outages. 

Once everything is set, hackers signal botnets to access the targeted site. The sudden surge in traffic takes a toll on its services, leading to slowdown or complete shutdown. 

IP spoofing and amplification are the most popular techniques used by hackers in this cyber attack. In IP spoofing, hackers hide their real IP address in order to avoid detection. On the other hand, in amplification, weaknesses in the target server or sites are identified to multiply the malicious traffic. 

Types of Flood-Based DDoS Attacks

Denial of service attacks can be broadly categorised into three categories: volume-based attacks, protocol attacks, and application layer attacks. Here is the detailed information about each of these attacks. 

Volume-Based Attacks

This is one of the most common types of attacks, generally used by attackers. In this, the target site is flooded with a huge amount of traffic, leading to saturation of its bandwidth. 

UDP floods and ICMP floods are two common types of methods used in this type of attack. UDP floods overwhelm a target by sending large volumes of User Datagram Protocol packets to random ports, forcing the server to respond repeatedly. ICMP floods bombard the target with ping requests, causing it to use resources replying to each one, slowing or crashing the system.

The size of volume-based attacks is measured in bits per second (bps), and it can go up to gigabits per second (Gbps). DNS amplification is the most commonly used technique in this attack. Mirai botnet is the perfect example of volume-based attacks. 

Protocol Attacks

Protocol attacks are concerned with finding loopholes and weaknesses in protocols like TCP/IP.

They mainly affect the network and transport layers, consuming server resources and overloading communication devices like firewalls. 

Examples like SYN floods overwhelm servers by sending many connection requests without completing them. Ping of Death and fragmented packet attacks exploit weaknesses in how data packets are handled, causing crashes or freezes.

Protocol attacks are measured in packets per second (pps). You can mitigate the impact of a protocol attack by filtering out the bad packets before they reach the server. 

Application Layer Attacks

Also known as Layer 7 attacks, application layer attacks target weaknesses in the applications, causing them to fail. It also focuses on exhausting the resources of the targeted server by sending continued requests, appearing to come from a legitimate source. 

It includes HTTP GET or POST floods, where attackers send numerous seemingly legitimate requests to overwhelm a web server. These attacks target the application layer, making them harder to detect because the traffic looks like normal user activity.

The measuring unit of application layer attacks is requests per second (rps), and it is difficult to detect them as they look legitimate in nature. 

Signs of a DDoS Attack

There are numerous signs that can help you identify whether you have been attacked by DDoS or not. Here are the five most prominent signs to look for:

Sluggish Website Speed

If your website is taking time to load, then it is a sign of an attack. The attackers flood the website server with a hefty amount of requests, loading the server. This overloads the server and slows down the website’s performance. 

Sudden Spike in Traffic

An unexpected and sudden spike in website traffic is one of the most common signs of a flood attack. You can check this out by going through your web analytics tool. If you see soaring traffic from the same IP address or location, most probably you have been DDoSed. 

Unexpected Errors and Timeouts

Many times, these attacks also lead to a surge in errors and timeouts, which are unexplainable and unexpected. The attackers overload the server with continuous requests, making it difficult to handle the requests, resulting in server errors. 

Increased Memory Usage

The climbing memory usage of the server can be an indication that your site is under attack. This is because hackers’ continuous requests soak up all the server memory, resulting in it turning unresponsive or slowing down to a turtle pace.  

Recent DDoS Attack Examples in 2024–2025

DDoS attacks have become sophisticated over time, targeting public and private organisations. As per the report by Cloudflare, in the final quarter of the year 2024, the attacks saw an 83% YoY (year-over-year) increase. 

Internet Archive Data Stolen

In October, a possible Russian-based group of hackers that goes by the name SN_BLACKMETA hacked the Internet Archive website based in the United States. The hackers allegedly stole data of 31 million users. 

Attack on Italian Government Websites

In December 2024, a professional group of hackers from Russia named Noname057(16) attacked ten government websites in Italy. It also includes the websites of the Foreign Ministry and Milan’s airport. 

Japanese Banks’ Websites Compromised

The two most popular banks of Japan, Mizuho Bank and Resona Bank, fell victim to a denial of service attack. This disrupted the day-to-day proceedings as people were unable to access the website, and even the mobile application wasn’t working. 

How to Prevent a DDoS Attack?

Preventing your website from a flood attack is a challenging task. However, it is possible with stringent security measures. There are numerous flood attack cybersecurity measures that can help you avoid being DDoSed. Here are a few of them:

• Rate Limiting: This allows you to restrict the number of requests a server can receive from a user or an IP address within a specific period of time. Rate limiting can help expose the attack and mitigate it, but they speed up.
• Monitor with Firewalls & Traffic Analytics: Traffic analytics tools and firewalls can help catch hold of traffic spikes in real time. You can set alerts or integrate it with SIEM platforms to control the situation before it is too late.
• Use Content Delivery Networks (CDN): CDN allows you to distribute surge traffic across multiple networks, helping in absorbing the load. The distribution of traffic ensures your original server is not overloaded.
• Regular System Updates: Updating security measures at regular intervals is integral for safeguarding against denial of service attacks. It involves updating security software regularly and familiarizing yourself with potential vulnerabilities and addressing them.
• Cybersecurity Training: This is what most organizations ignore. Regular training regarding cybersecurity threats and measures should be conducted. For this, advanced tools like Threatcop Security Awareness Training (TSAT) can be a good investment.

What to Do During an Ongoing DDoS Attack?

When under a DDoS attack, time is very crucial. Here are certain steps you can follow to alleviate the threat and secure your servers:

1. The first thing to do is assess the situation and run the DDoS mitigation tools. They will help to stabilize your servers.
2. Next is to use firewalls or traffic filtering tools and block the malicious IP address. You can also use geo-blocking to block traffic from a particular region.
3. Notify your stakeholders, and you can also inform your users. Maintaining transparency avoids confusion as users will understand the reason for their ability to reach the website.
4. The final step is to engage the incident response team. Start by gathering logs and checking traffic. Furthermore, apply pre-defined strategies and begin the pathway to recovery.   

Conclusion

DDoS attacks have become quite popular and a serious concern for organizations in the public and private sectors. They have jeopardized the functioning of business in the past and continue to do so. 

A well-maintained and sophisticated defence system that allows real-time monitoring has become the need of the hour. 

As these attacks can happen anytime and anywhere, you must also remain proactive and should not leave any loose ends, especially when it comes to cybersecurity. You can invest smartly and partner with reputable cybersecurity solutions providers like Threatcop to keep your infrastructure safe and secure.