# 4 Case study 3: the Mirai botnet

The Mirai botnet can launch highly sophisticated distributed denial-of-service (DDoS) attacks, which can overwhelm and cripple almost any website. In this section, you’ll look at how the Mirai malware infects Internet of Things (IoT) devices and harnesses their computer power to launch DDoS attacks.

## Activity 11

Allow about 15 minutes

1. You may not have met denial-of-service attacks. If not, you should visit Section 3.4 of OpenLearn’s Network security course and read the explanation about DoS attacks. Then visit How to Survive a Botnet Attack (also on OpenLearn) and watch the animated tutorial about botnets.

   You should open the links in new tabs or windows by holding down Ctrl (or Cmd on a Mac) when you click on the link. Return here when you have finished.

   Briefly explain what denial-of-service attacks and botnets are.

### Answer

Denial-of-service attacks prevent the normal use or management of communication services, and may take the form of either a targeted attack on a particular service or a broad, incapacitating attack. For example, a network may be flooded with messages that cause a degradation of service or possibly a complete collapse if a server shuts down under abnormal loading. Another example is rapid and repeated requests to a web server, which bar legitimate access to others. Denial-of-service attacks are frequently reported for internet-connected services.

(OpenLearn, no date)

The term botnet or ‘zombie army’ is used to refer to a number of computer networks that have become infected as a result of malicious third-party software sneaking onto a user’s computer and then linking it to others to send spam to, or steal data from.

(OpenLearn, 2011)

2. Now watch Video 2 which briefly explains what the Mirai botnet is. As you watch note down how the botnet attacks a website.

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Video 2 The Mirai botnet
Transcript
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OpenLearn - Learning from major cyber security incidents
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