When one or more of the attackers interfere with a service so that it cannot be delivered, it is technically known as a Denial-of-Service, or DoS, in short. DoS attacks are done by restricting access to servers, networks, applications, and services. While a DoS is achieved by a single system that sends malicious requests or data, a DDoS attack originates from more than one system.

Working Principle of a DDoS Attack

In general, DDoS attacks function by flooding a potentially vulnerable system with data requests. It may range from sending a large number of requests to a web server for serving a specific page so that it eventually crashes or hitting a database with an enormous volume of queries. The available internet bandwidth and the capacity of RAM, as well as CPU, become overwhelmed as a consequence.

DDoS Attack Classification

There are three major types of DDoS attacks. The modus operandi, however, remains the same in every case, which is to make online resources completely unresponsive or at least sluggish. Let’s discuss each in detail.

Volume-Based Attacks

Volume-based attacks rely on colossal amounts of useless traffic for overwhelming a network resource like a server or a website. They include user datagram protocol, internet control message protocol, and spoofed packet flooding. The size of any such attack can be measured in bits/second or bps.

Network- or Protocol-Layer Attacks

Network- or protocol-layer attacks transmit a massive volume of packets to the infrastructure management tools and network infrastructure that are being targeted. These types of attacks involve Smurf DDoS and SYN (short for synchronize) floods, among others. Their size can be measured in packets/second or PPS. Note that the SYN floods are also known as half-open attacks.

Application-Layer Attacks

Application-layer attacks include flooding applications with malevolent requests. The size of any such attack can be measured in requests/second or rps.

DDoS Attack Symptoms

A typical DDoS attack can be seemingly identical to several of the non-malicious scenarios that are usually associated with availability issues, for instance, a downed system or server, legitimate requests in humongous volumes from legitimate users, or even a broken wire. It often calls for a critical analysis of the network traffic to figure out what is exactly going on.

DDoS Attack Tools

DDoS attackers generally utilize botnets, which refers to a network of systems that are infected with malware and can be controlled centrally. Although these infected endpoints typically happen to be servers and computers, they also affect internet of things and mobile devices of late.

The DDoS attackers are to identify potentially vulnerable systems in the first place so that they can infect them by means mass infection measures, including malvertising as well as phishing,  and harvest those systems eventually. The attackers are also known to increasingly rent botnets from their inventors.

DDoS Amplification Types

Cyber-criminals flood a domain name system server with seemingly legitimate service requests in a DDoS amplification attack. The attacker can intensify DNS queries by leveraging different techniques. The attackers often use botnet, into an exceptionally large volume of traffic aiming to hit the targeted network. It effectively consumes the bandwidth of the victim in the process.

Chargen Reflection

It is a derivative of the original DDoS amplification attack that works by exploiting Chargen, which is rather an archaic protocol first introduced in 1983. The idea is to send small packets with a spoofed internet protocol of the victim being targeted to devices that form the internet of things and also operate Chargen. To put things into perspective, a vast majority of the web-enabled printers and copiers utilize this particular protocol. The devices then drown the target with user datagram protocol packets, which the target is not able to process anymore.

DNS Reflection

It is an offshoot of the original DDoS amplification attack that is widely used by cyber-criminals. Businesses or consumers with routers or other gadgets whose DNS servers are not configured properly are the most susceptible systems to these attacks.

In this process, the attacker transmits spoofed DNS queries that seem to originate within the target’s network. So, the DNS servers correspond with the address being targeted. The attack is further amplified by querying several DNS servers.

DDoS Digital Attack Map

The Digital Attack Map or DAP utilizes information from over three-hundred and thirty internet service providers that share attack and network traffic data anonymously. The DDoS DAP offers a global perspective on where distributed denial-of-service attacks are happening with hourly information updates.

Summary

A distributed denial-of-service attack refers to a malicious exercise of crashing an online system or a web server by flooding it with user requests. DDoS attacks can be instigated by revenge, hacktivism, or may turn out to be a simple act of mischief, and range from trivial annoyance to significant downtime leading to loss of business.

At Zenmid, we help protect your business from hacker attacks and safeguard your brand equity. We specialize in providing comprehensive cybersecurity solutions customized to deliver exceptional customer experience and ensure compliance.