Information Security Basics
Which statement correctly describes a DDoS attack?
- AAn attack that tries passwords by brute force from a single computer
- BAn attack that sends a huge amount of traffic at once from many devices, such as a botnet of malware-infected machines, so that a server or line cannot provide service
- CAn attack that intercepts communication along the way to eavesdrop on or alter its contents
Show answer and explanation
Answer: B. An attack that sends a huge amount of traffic at once from many devices, such as a botnet of malware-infected machines, so that a server or line cannot provide service
A DoS (denial-of-service) attack sends huge amounts of traffic or processing requests to exhaust the capacity of a server or line so that legitimate users cannot use the service; of the three elements of information security, it compromises availability. A DDoS (distributed denial-of-service) attack does this from many devices at the same time, often using a botnet, a collection of malware-infected PCs, routers and IoT devices such as surveillance cameras. Because the sources are spread across many machines, simply blocking traffic from specific IP addresses is hard. Countermeasures combine DDoS protection services offered by carriers or CDNs, detection and throttling of abnormal traffic, and building spare capacity into the system.
- A. Trying passwords by brute force from one computer is a brute-force attack. The aim of a DDoS attack is to make the service unusable.
- B. Correct. Sending huge amounts of traffic from many devices at once to disrupt service is a DDoS attack.
- C. An attack that intercepts communication along the way is called a man-in-the-middle attack.