A DoS attack is similar to a DDoS attack, except they take very different forms. DoS attacks exist in one of two broad classes, Denial-of-Service (DoS) and Distributed Denial-of-Service (DDoS).
DoS attacks are perpetrated by a single attacker and their goal is to make an application, service or machine unavailable. This is done by either flooding it with more requests than it can handle or otherwise consuming resources or processing in such a way that legitimate requests cannot be handled.
Within DoS, there are two primary categories:
DDoS attacks are denial-of-service attacks in which more than one attacking machines participate. The proliferation of IoT devices with poor security controls has led to a massive rise in such attacks including botnets such as Mirai.
The operators of these botnets can even rent them out to other malicious actors to fuel devastating DDoS attacks - such as the one against Dyn that crippled large parts of the internet in 2016.
DDoS attacks can also be perpetrated by large groups of active users using simple tools like in the DDoS attack by the Anonymous hacker group. The hacker group had used a free internet tool called Low Orbit Ion Canon (LOIC) to conduct online attacks against computer systems. The group had caused multi million-pound losses to a number of firms, including PayPal and Ministry of Sound, as a revenge for the backlash against WikiLeaks.
The bottom lineWith the increase in the dependency of smart devices among the consumers, it is estimated that the DDoS attacks are not going away anytime. Hence, organizations manufacturing and selling all IoT and consumer smart devices need to adhere to specific security requirements to prevent cybercriminals from building an army of botnets. To state it in the best way, the UK government has proposed new IoT security laws to help protect UK citizens and businesses from the threats posed by cybercriminals increasingly targeting IoT devices.