What is a Denial-of-Service (DoS) Attack?
If you've been paying attention to the news lately, chances are, you may have heard the term 'Denial-of-Service' (DoS) attack. But what is a DoS attack, and why should we care about it? In this article, we'll take a deep dive and explore the ins and outs of DoS attacks, shedding light on the impact they can have on businesses and society as a whole.
DoS attacks are a type of cyber-attack that aims to make a website, web application or network unavailable to its intended users. When a DoS attack is launched, it overloads the targeted system, rendering it unusable by either flooding it with a massive number of requests or by exploiting vulnerabilities in its infrastructure.
The primary objective of a DoS attack is to disrupt the normal operations of a website or service. For instance, an ecommerce business may be targeted to take their website offline, thus preventing customers from buying goods or services. Similarly, DoS attacks on hospital networks or government websites could be dangerous and have potentially life-threatening consequences.
Why are DoS attacks carried out?
There are multiple reasons why individuals and groups may resort to carrying out DoS attacks. The most common motivations include vandalism, revenge, ideological differences, monetary gain, and activism. Some attackers may carry out DoS attacks as part of their agenda, hoping to impact the operations of a company or cause them financial harm, while others use DoS attacks as a distraction tactic to divert attention from more significant attacks that are being carried out simultaneously.
Types of DoS Attacks
There are different types of DoS attacks; the most popular of which are:
1. Volume-based attacks: A volume-based attack works by overloading the bandwidth of the targeted system with massive traffic volumes. The system is overwhelmed, unable to handle the traffic surge and crashes in response. The traffic could be generated from bots or malware-infected devices. In recent years, botnets have become a popular tool used to execute volume-based attacks massively.
2. Protocol-based attacks: Protocol-based attacks target the IT equipment's network layer and applications, such as DNS or HTTP. The attacker usually exploits vulnerabilities in the protocol stack to create errors, thus causing the IT equipment to crash.
3. Application-layer attacks: These types of attacks occur when an attacker exploits a vulnerability in an application or software running on the target system. The attacker then releases a virus or trojan which sends requests to the server, crashing it.
Once a DoS attack has been launched, it can be challenging for the targeted business to mitigate its effects. The attacks usually consume the company's resources, making it impossible for users to access the service. Indeed, DoS attacks can be a serious threat to any business.
Preventing DoS attacks
One of the most effective countermeasures that businesses can take to prevent DoS attacks is to set up multi-layered security protocols. These can include firewalls, intrusion detection software, and filtering systems that are designed to recognize and block various types of attacks. In addition, website owners can employ mitigation services or work together with their internet service providers (ISPs) to help them block malicious traffic before it reaches their servers.
Practical Examples of DoS attacks
Some of the most famous DoS attacks in recent years include the following:
1. The 2021 Microsoft Exchange Server zero-day vulnerabilities - This attack saw a group of Chinese hackers exploit four critical vulnerabilities in Microsoft's Exchange email services to receive emails from specific targets.
2. The 2016 Mirai Botnet attack - This was a massive attack that targeted thousands of IoT devices, such as home routers and security cameras. The Mirai Botnet consisted of these compromised connected devices, which were used to send traffic to their targets.
3. The 2012 DDoS attack on major U.S. banks - A large-scale DDoS attack targeting major U.S. banks like Bank of America, Chase, and Wells Fargo was launched. The attackers brought down banking sites and disrupted online banking services, causing chaos for customers.
As can be seen from the above examples, DoS attacks can have serious consequences for businesses and society as a whole. They can cause loss of data, loss of operational time, and potentially wreak havoc on individuals' personal lives. It's imperative for companies to understand the risk that DoS attacks pose and to take a proactive approach to counter them. And always remember, while businesses can implement measures to prevent DoS attacks, it is essential to remain vigilant and stay safe while using the internet.