A Denial-of-Service (DoS) attack is a type of attack that is intended to cripple or shut down a machine or network.
A DoS attack makes the target inaccessible to its users by disrupting its normal functions. The attacker accomplishes this by flooding the target machine or server with traffic and requests, or constantly sending it information, overwhelming it and triggering a crash.
DoS attacks almost always go after high-value targets such as servers or websites of multinational corporations, big banks, government websites, media companies, or trade organizations.
Types of DoS attacks
There are two types of DoS attacks. These are crashing services and flooding services.
- Crash attacks exploit vulnerabilities in the system or server that they are targeting, causing it to crash. The malicious actor sends an input that exploits bugs, causing the system to destabilize or crash entirely.
- Flood attacks work differently, where the attacker floods the system or server with too much traffic, rendering the server unable to process the information, causing them to slow down or stop entirely. There are different types of flood attacks.
Types of Flood DoS attacks
- Buffer overflow attacks – This is the most common type of DoS attack, where the attacker sends significantly more traffic to a network than what it is designed to handle.
- ICMP flood – This type of attack sends spoof packets that ping all computers part of the targeted network. As a result, the network amplifies the traffic. This type of attack is also known as the “ping of death.”
- SYN flood – In this type of attack, a request to connect to the server is sent but never completed. The attack continues until all ports are saturated, with no port free for legitimate users to access.
As the cryptosphere and DeFi are completely decentralised and dependent on servers and internet connections, they get targeted more and more as well.