DDoS attack, also known as a Distributed Denial of Service attack is a malicious attempt to render an online service, network or website unavailable to its intended users.
A DDoS attack is sent by a large number of computers, using either flood attacks, which involve overwhelming a server with traffic, or direct denial-of-service (DDoS) attacks, which are designed to take down a system, by exploiting its vulnerabilities.
The DDoS attack is usually launched from many computers simultaneously, all of them having the same target. The attackers utilise large-scale networks of hundreds of thousands of computers that have been infected with malicious software, allowing them to be controlled remotely and used in the attack.
The attacker can choose to use specific methods, such as flood attacks, in which a large amount of data is sent to the target from multiple systems; distributed denial-of-service (DDoS) attacks, which involve sending multiple requests to the target system, sometimes slow posing the system to a halt; and application-level attacks, which involve exploiting an application’s vulnerabilities to gain access.
In addition, attackers may also use brute force attacks by flooding the target system with requests that exhaust its computing resources, or by using botnets to bombard the target with malicious packets.
Once the attack has begun, it is difficult to influence the outcome, as the attackers are able to control the size, duration and sources of the attack. However, there are mitigation techniques such as traffic shaping, load balancing and IP blocking to reduce the effects of the attack.
DDoS attacks are increasingly becoming a major threat to companies and organisations, as they are difficult to predict, protect against and detect. It is, therefore, important for companies to implement appropriate security measures and to monitor their networks for unusual activity.
