Mirai IoT Botnet

Target Audience

Undergraduate
Graduate

Keywords

Mirai
DDoS attacks
IoT security
Malware

Introduction

Overview

In 2016, the Mirai botnet was responsible for one of the largest DDoS attacks in history, targeting Dyn, a DNS provider. Mirai worked by scanning the internet for vulnerable IoT devices, often protected by default or weak credentials, and using them to launch massive attacks. Its source code was later released publicly, leading to many variants.

Vulnerability Details

Mirai infected various IoT devices such as cameras by exploiting weak or hardcoded default credentials. The malware turned these devices into a botnet capable of generating up to 1.2 Tbps of traffic. It used DNS amplification and other reflective DDoS techniques to overwhelm services. Mirai's infrastructure included bots, scanners, loaders, and command-and-control servers. A single manufacturer's unsecured webcams were responsible for a significant portion of the traffic. Once its source code was released on GitHub, attackers began developing new variants. The Mirai case demonstrates the need for stronger IoT security practices, such as password changes, firmware updates, and network segmentation.

Learning Objectives

Explain DDoS attacks
Explain Mirai IoT malware
List common protection mechanisms for DDoS attacks

Download

Includes a PDF case study adapted from a real-world cyber breach
Guided questions for student engagement
Instructor materials including context and background
All content packaged in a downloadable ZIP file

Remote Terminal

Terminal Description

Module Questions

What happened during the Mirai IoT botnet attacks of 2016?IoT devices were used to spread ransomware to corporate networks.The Mirai botnet exploited IoT devices with weak security settings to carry out massive Distributed Denial of Service (DDoS) attacks on major websites and services.Hackers stole sensitive data from IoT devices and sold it on the dark web.Mirai targeted only mobile devices, shutting down global cellular networks.

What are two effective security mechanisms to prevent vulnerabilities in IoT devices like those exploited by the Mirai botnet?Require unique, strong passwords for all devices and ensure firmware updates are regularly applied.Disable firewalls to improve device performance.Only use encryption when sending data over local networks.Allow default passwords to stay unchanged for ease of use.

How can companies defend against DDoS attacks originating from botnets like Mirai?Increase bandwidth to handle all incoming traffic without restrictions.Only allow traffic during business hours.Use DDoS mitigation services, implement rate limiting, and deploy Web Application Firewalls (WAFs) to block traffic from malicious sources.Shut down all external-facing services.

How can organizations enhance security monitoring for IoT networks to detect malware like Mirai?Perform manual device checks only once a year.Disable logging to save storage space.Only monitor traditional IT devices, ignoring IoT systems.Implement network traffic analysis tools, deploy Intrusion Detection Systems (IDS) specifically designed for IoT, and use automated threat intelligence to detect suspicious behavior.

What IT weaknesses were present in IoT devices targeted by Mirai?Constant firmware updates that slowed device performance.Use of default or weak credentials, lack of automatic firmware updates, and poor access control settings.Excessive monitoring of internal traffic.Strong, unique passwords on all devices.