What Is a Botnet?
A botnet is a network of Internet-connected devices infected with malware that’s controlled remotely by threat actors. These devices are used for a variety of purposes, including sending spam emails, conducting click fraud, and launching distributed denial-of-service (DDoS) attacks.
There are different kinds of botnets, each with their own capabilities and targets. Some botnets are designed to steal data, while others attack infrastructure, businesses or individuals. Botnets can also be employed for financial gain, such as ransomware or generating malicious traffic for ad fraud campaigns.
In the most basic kind of botnet, bot software on infected machines listens for instructions from a central command and control (C2) server. The bot-herder then pushes commands to the infected computers, such as downloading more software or initiating a distributed denial of service (DDoS) attack. This centralized approach is relatively easy to shut down. System administrators and law enforcement can simply identify the C2 server and block its communications, or seize the domain that’s being used.
Other botnets are more sophisticated, communicating via peer-to-peer networks (P2P) or a centralized IRC network and domain. It’s more difficult to take down these specialized botnets, as they rely on the trust and cooperation of all hijacked devices.
To prevent your device from becoming part of a botnet, make sure you’re keeping up with patches and security updates for your operating systems, browsers and apps, as well as your IoT hardware. You should also avoid buying hardware from manufacturers who don’t offer good support or don’t have a reputation for quality. Lastly, reboot your IoT devices on a regular basis to help limit the chances that they will be hacked.