Denial-of-service (DoS) attacks are a well-known form of cyber-attack that seeks to render a website or network inaccessible to users by overwhelming it with traffic. In the digital age, DoS attacks have become increasingly popular, with their misuse causing a significant impact on businesses, individuals, and the wider community. With that in mind, in this article, we aim to explore what a DDoS attack is and why it is such a devastating tool for cybercriminals.
## What is a Denial-of-service (DoS) attack?
In the simplest of terms, a DoS attack is an attempt to exhaust the resources of a computer system by overwhelming it with traffic from one or multiple sources. The goal of a DoS attack is to make the targeted system or website inaccessible to its legitimate users. It is a technique used by cybercriminals to disrupt and control systems through a vast array of methods, including flooding the system with traffic, sending it malformed packets, and exploiting vulnerabilities related to software, hardware, or operating systems.
## Types of Denial-of-service attacks
There are several types of DoS attacks that cybercriminals can use to breach a network or website. Some of the most common DoS attack types are:
### 1. Distributed Denial-of-service (DDoS) attack
This type of attack floods a network or website with traffic from multiple systems to overload the system and make it inaccessible to its legitimate users. DDoS attacks often use bots or zombies, which are infected computers that are controlled remotely by the attacker called a botnet. Botnets are a network of computers that can be harnessed together to unleash a DDoS attack. Think of it as a combined powerful force that can bring down a website or network. And with botnets, attackers don't even need access to the computer or device as they can use bots to launch their attacks.
### 2. Application-layer DoS (ALDoS) attack
Application-layer DoS (ALDoS) attacks are an attempt to overload a web server's application layer. The application layer is responsible for processing incoming client requests, so by repeatedly sending inefficient or malicious requests to the server, it can be crashed. An example of an application-layer attack is sending a flood of requests to an online shopping site's checkout process. By making a surge of requests, the checkout process can be overwhelmed, which leads to a failed or denied service for legitimate users.
### 3. Ping flood attack
A ping flood is when an attacker sends an overwhelming number of pings (requests) to a computer, which causes the system to slow down or crash. Pings are like virtual handshakes, and their goal is to test the connection between two devices. In a ping flood attack, the cybercriminals use masses of pings to overwhelm the target computer, causing the system to crash.
### 4. SYN Flood attack
A SYN Flood attack is a DoS attack that targets the TCP/IP connection establishment process. When a connection occurs between a client and a server, the process begins with a SYN packet, in which the server expects to receive an ACK packet in return to complete the connection. In SYN Flood attack, the attacker sends multiple SYN packets, spoofing their IP address, and expecting the server to respond and use resources to wait for the ACK packet. If the server waits too long, the connection will time out, and the server will treat it as an attempted DoS attack.
## Why are Denial-of-service attacks dangerous?
DoS attacks can cause significant damage to organizations, businesses, governments, and individuals. Here are some of the dangers of DoS attacks:
### 1. Financial loss:
For businesses, a DoS attack can have far-reaching financial consequences. If customers cannot access a company's website, then they cannot purchase goods or services, leading to a loss of revenue, customers, and profits. Additionally, companies may be taken offline for extended periods of time because of DoS attacks, leading to a loss of productivity and income.
### 2. Loss of credibility:
For businesses and organizations that rely on their online presence, a DoS attack can lead to a loss of credibility and trust. Customers may view a business that was taken down by a DoS attack as unreliable and untrustworthy. The negative impact on the reputation of the organization can lead to long-term problems, including loss of customers and difficulty in attracting new ones.
### 3. Cybersecurity risks:
DoS attacks can be used as a diversionary tactic to distract cybersecurity teams from other breaches or attacks. By overwhelming the resources of the system, cybercriminals can gain unauthorized access or implant malware in a targeted system.
In conclusion, DoS attacks are a serious threat to individuals, businesses, and organizations worldwide. With an increasing number of businesses and individuals relying on online platforms and services, it is more important than ever to take steps to protect against DoS attacks. While there is no silver bullet to stop DoS attacks, there are strategies and measures organizations can take to mitigate the damage and disruption caused by these attacks. Always keep your systems updated, monitor incoming traffic and analyze network traffic for any suspicious activity. Remember, an ounce of prevention is worth a pound of cure!