A threat analyst obtains an intelligence related to a threat, where the data is sent...

A threat analyst obtains an intelligence related to a threat, where the data is sent in the form of a connection request from a remote host to the server. From this data, he obtains only the IP address of the source and destination but no contextual information. While processing this data, he obtains contextual information stating that multiple connection requests from different geo-locations are received by the server within a short time span, and as a result, the server is stressed and gradually its performance has reduced. He further performed analysis on the information based on the past and present experience and concludes the attack experienced by the client organization.

Which of the following attacks is performed on the client organization?