Understanding and Preventing DDoS Attacks

What are DDoS Attacks?

When browsing the web, it is pretty common to encounter a situtation  in which a web page either loads slowly or fails to load altogether. Many believe that it is due to their Internet connection, but it is not always the case. When a large number of requests to a server happen at once, then the server can be clogged and work slowly. Such a phenomenon is known as Distributed Denial of Service

DDoS, short for Distributed Denial of Service, represents a cyberattack that targets online services like networks, web and mobile apps with the intent of making it unavailable to users. The attackers aim to overwhelm the normal function of an organization's systems or operations, thus making the online services flooded with more traffic than it can handle. These attacks can persist for days or even longer periods, causing significant disruption.

How DDoS attacks work?

DDoS attacks work under a very simple yet potent principle: flood a target server, service, or network with a flood of malicious traffic, making it unavailable to legitimate users.

Preparation phase

• The attacker identifies potential victims vulnerable to DDoS attacks. 
• They gather or infect hundreds or thousands of compromised computers or devices turning them into botnets. 
• Using tools and techniques to hide the identity of the attacker and bypass security measures.

Attack execution

• The attacker sends the botnets to flood the target organization with a huge number of requests or traffic.

Effect of the attack

• Causing the targeted company’s online resources to be overwhelmed bringing its services down.
• Implications include lost business opportunities, lost revenue, reputation, and customer trust.

Countermeasures

• DDoS mitigation services or security solutions to manage spikes in traffic and to filter out the malicious. 
• Load balancing techniques and network infrastructure scaling helps not to be overloaded by the attack impact. 
• Legal action might also be followed up to identify and prosecute the attacker.

What are the types of DDoS attacks?

A network consists of seven distinct layers that make it capable of communicating with other networks. Because each layer specifies definite actions and needs specific tools and tactics to be used to penetrate it, DDoS attacks can be divided into different types according to the layer they target and the actions they try to emulate.

• Application Layer Attacks: This type of attack targets the software or applications. We can suppose a person tries to bombard a website with thousands of fake requests for information. The website spends so much time trying to respond to all these fake requests that it slows down and eventually crashes. This sort of attack can be used to target specific functions of an application, such as trying to overload a messaging service by sending millions of fake messages.
• Protocol or Network Layer Attacks: These types of attacks target exploits of network protocols or infrastructure. A known example is the SYN flood attack, in which a server is overwhelmed with a large number of TCP SYN packets, consuming server resources and inhibiting legitimate connections from being established. The computer gets so busy dealing with all these fake requests that it can't handle legitimate requests from other computers, therefore slowing it down or crashing the computer altogether.
• Volumetric Attacks: these attacks are a type of DDoS attack that aims at overwhelming the network bandwidth of the targeted site with a flood of traffic. In fact, they overwhelm the target with a tremendous amount of data that saturates the network infrastructure of the target, slowing it down or rendering its services unavailable. Examples include UDP floods, in which an attacker floods a target with a large number of User Datagram Protocol (UDP) packets, and ICMP floods, wherein an attacker overwhelms the target with ICMP packets. 
• Teardrop Attacks: A teardrop attack is when a cybercriminal sends huge packets into several small packets targeted at the victim system. However, the abnormal fragmentation of the packets is carried out by the attacker to eventually disrupt the reassembly process by the targeted system. From this, the attack  exploits the IP protocol which might lead to destabilization of the targeted system.

Why are DDoS attacks dangerous?

DDoS attacks are a pain in the neck for CISOs because they are easy, they are cheap to launch, and the losses for an organization can often come in the millions of dollars in remediation costs, lost revenue, decreased productivity, loss of market share, and damage to the brand reputation. 

• Productivity Disruption: DDoS attackers send a huge flood of traffic toward targeted systems or networks, making these systems or networks unreachable for legitimate users. The type of disruption that will be created by such an incident is very serious for a business, an organization, or even for an individual when services necessary for a critical operation are incapacitated.
• Financial losses: Because DDoS attacks lead to downtime, this means serious financial losses for companies. These include revenue losses due to the interruption of services, mitigation costs, and the potential for penalties due to failure to meet service level agreements.
• Brand Reputation Damage: Long-term downtime or disruption caused by DDoS attacks can indeed damage the reputation of businesses or organizations. Customers will start to lose trust in the reliability and security of the affected services, hence leading to long-term damage to reputation and loss of customers.
• Risk of data breach: DDoS attacks might be a diversion or a mask of something more dangerous, such as getting through the network or collecting sensitive data. It is a primary factor of data breach and compromise to sensitive information.
• Resources Consumption: DDoS attacks consume valuable resources like network bandwidth, server capacity, and personnel time to mitigate and recover from the attack. This could be especially stressful because it could consume a lot of resources, particularly critical resources, and divert attention and resources from other critical tasks and operations.

Best methods to prevent DDoS attacks

• Use a Firewall: it is a tool that lies between internal networks and the internet. It inspects all inbound and outgoing traffic according to the set rules. In the event of a DDoS attack, firewalls can be set to block such traffic, thus preventing it from flooding network resources and causing the damage. More than that, firewalls help identify and reject traffic from known malicious sources, thus increasing the security of a network against DDoS attacks.
• Limit Connections: limiting the number of simultaneous connections from an IP address or session is a way to mitigate DDoS attack damages. This helps an organization control the number of requests that are dealt with. This helps in preventing overload of traffic, thus making network resources available to valid users. Since malicious actors cannot flood the system with many requests, this reduces its effect on the network.
• Consider Network Segmentation: this is a practice where a larger network is divided into smaller, isolated segments. This helps in providing hardy protection from DDoS attacks. The process of dividing the network into small pieces confines the spread of DDoS attacks and reduces its effect on critical systems and services. In the event of an attack to a specific segment, other parts of the network remain intact and continue to operate. This ensures that operations are not affected. Network segmentation also allows for more traffic control and monitoring, thus allowing DDoS threats to be quickly detected and acted upon.
• Use one or more Load Balancers: it is important to distribute the incoming network traffic across multiple servers or resources equitably and to ensure equitable distribution of workload and resilience against DDoS attacks. Equitable spread of loads reduces risks related to server overload and performance degradation even for fairly continuous and large-scale DDoS attacks. Load balancers can, in addition, recognize and reroute the traffic away from the servers under attack by the DDoS, which reduces the burden on the network resources and ensures service delivery remains intact.
• Use Intrusion Detection and Prevention Systems: Intrusion Detection and Prevention Systems are the vital tools for the detection and response to DDoS attacks in real-time. They monitor the network traffic for abnormal traffic patterns and signs of malicious activity to detect and respond to DDoS threats. These systems automatically take responsive actions such as blocking or throttling of traffic to reduce the attack impact. Hence, by proactively detecting and responding to threats, IDPS ensures that the availability of services is maintained and risks for service disruption are minimized.

These are strategic measures that, when combined, help organizations mitigate and reduce the impact of DDoS attacks on the systems and services that it uses. By adopting a blend of proactive measures and reactive strategies, organizations can provide high resilience to DDoS attacks and protect the availability and integrity of their network infrastructures.

Final Thoughts

A DDoS attack paralyzes normal users from accessing websites and services online. It costs a lot of money and damages the reputation of an individual or organization.

The good news is that preventing and even stopping these attacks is possible. Through smart action, people and companies can make things more difficult for attackers to interrupt their online stuff.