What we work with

The purpose and result of Denial of Service attacks is to disable access to services. This may happen through the utilisation of a weak point in the application, when the server stops communicating after sending off a specific chain. This may also include the misuse of an error, reaching the limit of the system, network card, application or system resources such as CPU, memory, disk space or IO operation. A DoS always happens when the particular server service returns unavailability results from the attack.

The difference between DoS (Denial of Service) and DDoS (Distributed Denial of Service) is only in the number of the attacking machines. In the case of a conventional DOS attack, only one machine is engaged; in the case of DDoS, at least two machines are engaged; in simultaneous DDoS attacks, tens of thousands to hundreds of thousands stations are engaged (incl. e.g. smart appliances).

However, unavailability of the system itself may not be the main objective of the attacker. In attacks of the type, Brain Denial-of-Service (BDoS), this is only pretence. During the course of the attack, the administrator deals with overloading of the server and usually pays less attention to the rest of the system that does not show any anomalous behaviour. This is utilised by the attacker who carries out his real intent in the part of the infrastructure to which the administrator does not pay proper attention. This may be represented by e.g. a theft of sensitive information by breaking through the protection of the server by another, less visible type of attack.