Distributed Denial of Service Attacks (DDoS Attacks) are a malicious attempt to disrupt the normal traffic of a targeted computer system or network and make it unavailable to it’s end users. This happens by sending more traffic that the target is capable of handling, which causes it to stop providing service to its normal users.
How Does a DDoS Attack Work?
Web servers and network resources have a limit on the number of simultaneous requests they can handle. The channel connecting the server to the Internet also has a finite bandwidth capacity. If the number or volume of requests exceeds any infrastructure component’s capacity, the service level will likely suffer in the following ways: You may experience a slower response time than usual or some (or all) requests may not be answered by the server.
Cybercriminals use DDoS attacks to send malicious code to a number of vulnerable computers and instruct them to make requests to a singel server. This is often done using tools such as a botnet. The botnet could be a network made up of private computers infected via malicious software. Exploited computers can also include IoT devices and other networked resources. DDoS attacks are more effective when multiple compromised computers are used as source of attack traffic.
Botnets target victim’s server or network by sending requests (small data packets) to their IP address. This can potentially cause an overload of the server or network, which could lead to denial-of-service to the normal traffic. It can be difficult to separate attack traffic and normal traffic because each bot is an actual Internet device.
Common Types of DDoS Attacks
01. UDP Flood Attack
This attack involves sending large numbers of User Datagram Protocol packets (UDP) to a server to disrupt its functioning. Firewalls that are put in place to defend against such attacks may become exhausted and stop protecting your online activities.
02. Ping of death DDoS attack
Ping of Death refers to a type of DDoS attack that attempts to destabilize or freeze a computer or service. This is done by sending larger packets via a simple ping command. Some ping packets may be small but IP4 ping messages can reach 65,535 bytes. TCP/IP systems that cannot handle larger packets than this are therefore vulnerable to larger packets. If a maliciously large package is sent from the attacker to the targeted server, it will be fragmented into small pieces. Each piece must not exceed the maximum size limit. When the target machine attempts putting the pieces back together, the total packet size can exceed the size limit. If this happens, the machine will freeze, crash, or reboot.
03. SYN Flood Attack
SYN floods (half-open attacks) are a type of DDoS attack that attempts to block legitimate traffic from a server by using all the server resources. SYN flood attacks exploit the TCP connection’s handshake process. The attacker can overload all ports available on the targeted server by repeatedly sending initial connection request packets (SYN). This causes legitimate traffic to be slowed down or not to respond at all.
04. Ping (ICMP) flood DDoS attack
A ping flood is a type of denial-of service attack that attempts to overwhelm a target device using ICMP echo request packets. This causes the target to become unaccessible to normal traffic. Ping Flood attacks use the Internet Control Message Protocol (ICMP) as a layer protocol that network devices use to communicate. If the attack traffic is from multiple devices, it becomes a DDoS (distributed denial-of service attack).
05. Slowloris DDoS attack
It is an application layer DDoS attack that uses partial HTTP requests, called Slowloris. It opens and maintains many simultaneous HTTP connections between one computer and a targeted web server, and then keeps those connections open as long as possible. This causes the targeted server to be overloaded and slow down. Slowloris does not fall under any category of attack, but is a specific attack tool that can be used to disable a server from a single machine without consuming a lot bandwidth.
06. HTTP Flood DDoS Attack
HTTP Flood is a form of Distributed Denial of Service attack (DDoS). The attacker uses seemingly legitimate HTTP GET and POST requests to attack web servers or applications. It is designed to overload a target server with HTTP requests. After the target server has become overwhelmed with requests and is unable respond to normal traffic, additional requests from the real users will result in a DDoS attack. This flooding DDoS attack often relies on a botnet. A botnet is an Internet-connected group of computers that has been maliciously accessed through malware like a Trojan Horse.
07. NTP Amplification DDoS Attack
Network Time Protocol Amplification Attack (NTP) is a form of reflection-based volumetric Distributed Denial of Service (DDoS) attack that uses publically available NTP servers to overload the victim system with User Datagram Protocol (UDP) traffic.
How to Prevent from a DDoS Attack
There are multiple types of denial-of-service, so it is important to identify the most common signs. Intruders can cause a dramatic decrease in network performance or an increase of spam emails. Multi-level protection strategies are essential to secure your network, infrastructure, and applications. This includes prevention management systems that include firewalls, VPNs, anti-spam and content filtering security layers. This will allow you to monitor suspicious activity and identify traffic issues that may indicate DDoS attacks.
You can prevent a DDoS attack by taking the following security steps:
#1 Be aware of what traffic is normal and which is unusual
Understanding your website or server’s usual traffic patterns will give you a baseline. If you find that there is an excessive amount of traffic hitting your website or server, the baseline is to allow only as much traffic as the website or server can handle without affecting their availability. This is known as rate limiting. It places a limit on the number of times a user can repeat a specific action within a set time frame. This could be for trying to log in or trying to log out. It can stop some types of malicious bot activities by limiting the rate at which they are repeating their actions.
Advanced protection methods can also be used to analyze individual packets and determine if they are legitimate. To do this you must first understand the attributes of legitimate traffic, that will give you a baseline, and then you will be able to analyze each packet against these baselines.
#2 Take advantage of a CDN Solution
A CDN’s nature and ability to redistribute traffic as needed makes it an excellent defense against DDoS attacks. CDNs are distributed networks of servers that span the globe. They are used to store, share and deliver faster content. Many CDN providers offer different cybersecurity tools and features to help protect your website against hackers. You can also get free SSL certificates and DDoS protection, which will help you protect your application and server network from hackers.
A CDN is a way to balance website traffic and ensure that your server does not become overloaded. CDNs distribute your traffic to servers across the globe, making it harder for hackers to locate your actual server and launch attacks.
#3 Do a Network Vulnerability Analysis
Network vulnerability assessment is a process that scans for, detects, and analyzes security holes in corporate networks. It is vital that your organization conducts regular vulnerability risk assessments to ensure you find and address any potential weaknesses in your network.
The goal is to make it resilient to common cybersecurity threats. Your network vulnerabilities should be identified, and fixed, before a malicious user identify them. So you can patch up the infrastructure to better prepare for DDoS attacks or any other cybersecurity risk.
#4 Make Use of DDoS Attack Prevention Tools
Cloudflare DDoS protection protects websites, applications, and entire networks, while ensuring legitimate traffic is not affected. Cloudflare’s 100-Tbps network blocks an average 76 billion threats each day, including some of history’s most destructive DDoS attacks.
Cloudflare is a reliable company with a responsive and competent team. They have the ability to deflect even the most severe attacks.
02. AppTrana WAAP
It’s a Web application firewall with bot detection, DDoS protection, vulnerability scanning and bot control detection. AppTrana is unique in that it uses a risk-based approach to identify vulnerabilities and immediately patch them, providing tailored protection for APIs and web applications.
AppTrana guarantees zero false positives and combines expert-created surgically precise security rules with always-on security to ensure that applications and APIs are always protected.
AppTrana is a fully managed risk based Web Application and API Protection (WAAP).
This tool is comprehensive and can monitor many network events, including DDoS attacks. This tool logs and blocks IPs. You can quickly improve your security and demonstrate compliance by using a simple, affordable, and easy-to-use security information and event management system.
Security Event Manager includes hundreds of connectors that allow you to collect logs from different sources, analyze them, and then put it in a common readable format. This creates a central location where you and your team can easily investigate potential threats, prepare to audits, and store logs.
Another powerful WAF uses behavioral algorithms for detection and blocking attacks. With little to no configuration, you can immediately enable enterprise-class security. You can customize and integrate powerful integration options to tailor WAF policies to your specific security requirements.
This WAF checks all HTTP/HTTPS traffic and blocks any suspicious traffic. It also uses advanced Geo-blocking tactics.
These best practices can help you prevent DDoS attacks. They will also help you keep your server or website in good working order. DDoS attacks are a serious threat to your business. This is crucial for maintaining your server or website’s availability for your customers. DDoS attacks can cause business downtime which can result in loss of revenue and maintenance costs that could cost thousands of dollars.