What is a DDoS attack?

Introduction: DDoS attack

DDoS stands forDistributed Denial of Service. DDoS attacks are a malicious attempt to render a server, network, or service inaccessible to legitimate users by flooding the targeted server with overwhelming amounts of traffic.

Effective cybersecurity strategies are essential to safeguard servers and prevent downtime. This article will help users understand the types of DDoS attacks and leverage advanced DDoS prevention techniques. In doing so, organizations can stay ahead of DDoS attacks and maintain service availability.

What is a DDoS attack?

Unlike traditional denial-of-service attacks that originate from a single source, DDoS attacks leverage multiple compromised systems, often part of a botnet, to amplify the attack's scale and impact.

Key characteristics of DDoS attack

Distributed nature: The attack originates from numerous devices across different locations, making it difficult to pinpoint and block the source.

Overwhelming traffic: Targets experience massive amounts of data requests, slowing or halting service delivery to legitimate users.

Common types of DDoS attacks

Volumetric attacks: Aim to flood the network with excessive data traffic.

Example: UDP floods that exploit the User Datagram Protocol to overload the target.

Protocol attacks: Disrupt connections by consuming server resources or network devices.

Example: SYN floods that exploit vulnerabilities in the TCP handshake process.

Application layer attacks: Target specific applications or services to exhaust resources.

Example: HTTP floods that mimic legitimate user behavior to bypass security filters.

Real-world example: Stopping a DDoS attack with Darktrace’s AI-driven defense

In August, a corporate network faced a DDoS-related threat when a device exposed to the internet was compromised by XorDDoS malware—a botnet used for launching denial-of-service attacks. The attack began with thousands of failed SSH login attempts over several days, ultimately succeeding during early morning hours when the organization's security team was offline. This exemplifies attackers exploiting off-peak hours for greater impact.

Following initial access, the compromised device downloaded executable files disguised as text, initiating command-and-control (C2) connections to external servers. Despite firewall blocks, the botnet continuously attempted communication, generating hundreds of thousands of malicious requests before the device was quarantined. The delayed response, due to limited human availability, allowed the malware to establish a foothold.

Had Darktrace’s autonomous response system been fully active, it would have detected and automatically blocked suspicious activity following the malware download, preventing further escalation. The proactive AI-driven defense would have contained the breach, offering crucial time for security personnel to regain control and remediate the incident.

This case highlights the critical need for automated DDoS attack prevention during off-hours, as attackers increasingly exploit vulnerabilities when defenses are weakest. Leveraging real-time DDoS threat detection and autonomous response capabilities can significantly reduce risks, ensuring service continuity even in challenging scenarios.

How DDoS attacks impact businesses

DDoS attacks pose a significant threat to businesses, causing both immediate and long-term damage. A typical DDoS attack can cost businesses approximately $6,000 per minute, with an average duration of 45 minutes, leading to a total financial impact of around $270,000 per incident. The disruption can have severe consequences, including:

1. Loss of website availability

E-commerce platforms, financial services, and other online services depend heavily on uninterrupted access. A DDoS attack can completely block customer access, leading to missed sales opportunities and operational downtime.

2. Reduced customer trust and reputation damage

Frequent or prolonged service outages caused by a DDoS threat can harm an organization’s credibility. Customers may perceive the business as unreliable or incapable of securing its digital infrastructure, prompting them to seek competitors.

3. Operational disruption

Employee productivity can suffer if internal systems are affected. Additionally, IT teams must divert resources to mitigate the attack, delaying other critical projects.

4. Financial loss

Lost revenue from downtime, recovery costs, and potential fines for service level agreement (SLA) breaches can add up quickly. Large-scale attacks may cost businesses millions of dollars.

5. Security vulnerabilities

In some cases, DDoS attacks are used as smokescreens for other malicious activities, such as data breaches or malware deployment.

To mitigate these risks, businesses need robust DDoS prevention strategies that include real-time monitoring, threat detection, and automated response capabilities to maintain service continuity and protect their reputation.

For more information on the latest cyber threats download the Darktrace Half-Year Threat Report. Here our team of cyber analysts report on the top threat trends seen in our customer base.

How to detect a DDoS attack

Effective DDoS attack detection is crucial for minimizing the impact of these disruptive threats. Timely identification allows businesses to deploy defenses quickly and maintain service continuity. Several strategies and tools can help detect and respond to attacks in real time.

1. Traffic monitoring and anomaly detection

Continuous network traffic monitoring is essential for identifying unusual patterns such as sudden spikes in traffic or unexpected requests from unfamiliar IP addresses.

Advanced solutions use machine learning to detect these anomalies and differentiate between legitimate surges in traffic and malicious activity.

2. Rate limiting and threshold alerts

Setting limits on the number of requests a server will process in a given timeframe can help identify and block abnormal traffic patterns indicative of a DDoS attack.

Threshold alerts notify security teams when traffic exceeds normal levels, enabling rapid investigation.

3. Behavioral analytics

These tools establish a baseline of normal user behavior and flag deviations that may signal an attack.

They work effectively for detecting subtle or stealthy attack methods that might bypass traditional monitoring systems.

4. Automated DDoS prevention solutions

Cloud-based services can automatically detect and mitigate attacks in seconds, helping to maintain service availability even during ongoing threats.

These tools often offer real-time alerts and insights to aid in incident response and recovery.

How AI and machine learning can protect you from DDoS attacks

AI-based cybersecurity solutions, such as Darktrace, empower security teams by improving Mean Time to Detect (MTTD) and Mean Time to Respond (MTTR) when facing a DDoS attack. By continuously analyzing traffic patterns, AI tools detect deviations from normal behavior, enabling them to identify and mitigate attacks in real time, often before they escalate into full-scale threats.

Value of AI for real-time threat detection and defense

  1. Faster detection and response: AI-driven systems can process vast amounts of network data far more quickly than human analysts. This enables immediate identification of unusual traffic spikes or malicious patterns, leading to faster containment.
  1. Adaptive learning: Machine learning algorithms continuously evolve by learning from both successful and failed attempts to breach systems. This adaptability ensures that defenses remain effective even against emerging threats and evolving attack tactics.
  1. Autonomous protection: AI systems can autonomously take protective actions, such as throttling traffic, blocking suspicious IP addresses, or engaging black hole routing. This allows for continuous defense, even during off-hours when human intervention is limited.
  1. Operational efficiency: Automated threat detection reduces the burden on security teams, allowing them to focus on high-priority tasks rather than manually managing incident responses.

Business benefits

  • Minimized downtime: Proactive DDoS defense ensures that critical services remain available, reducing revenue loss and reputational damage.
  • Enhanced customer trust: Maintaining uninterrupted service during attacks helps businesses build trust with customers by demonstrating robust security measures.
  • Scalable protection: AI tools can efficiently handle threats regardless of the size or complexity of the attack, making them suitable for businesses of all scales.

By leveraging AI, organizations gain a dynamic and scalable approach to combating DDoS threats, ensuring stronger security and resilience.

Enhance your network security with Darktrace

While intrusion detection systems established essential monitoring capabilities decades ago, their signature-based approaches and passive nature leave organizations exposed to modern threats. NDR technologies address the fundamental limitations of IDS through behavioral analytics and machine learning.

Darktrace / NETWORK™ delivers the most advanced NDR capabilities, powered by Self-Learning AI that understands your unique environment without relying on outdated signatures or manual rules. Our multi-layered AI platform learns what constitutes normal behavior for an organization, identifying subtle anomalies that indicate genuine threats and filtering the false positives. Explore some of our Cyber AI insights to learn more about these capabilities.