Botnet

Each infected device is a bot, also called a zombie. It can be a computer, mobile device, or IoT device that is infected with malware and remotely controlled to perform a specific malicious task. The word botnet is formed from "robot" and "network."

Botnets typically grow by scanning the internet for vulnerable devices that can add computing power and capacity. They are used to conduct DDoS attacks, spread ransomware and other malware, run ad fraud campaigns, send spam, divert traffic, steal data, and manipulate social media and web content.

A joint government advisory described a botnet built on malware designed to hijack IoT devices such as webcams, DVRs, IP cameras, and routers running Linux-based operating systems. As of June 2024, its management database held over 1.2 million records of compromised devices.

To keep devices out of botnets, the FBI recommends disabling unused services such as Universal Plug and Play, remote management, and file sharing, replacing default passwords with strong ones, applying software and firmware updates, segmenting networks so IoT devices carry limited risk, monitoring for abnormal traffic volumes, and replacing end-of-life equipment. Rebooting a device can remove malware that runs only in memory.