What is a Botnet?
A Botnet is a network of malware-infected computers, servers, and IoT devices that work together to attack users or steal sensitive information. At the heart of every botnet is a malicious actor, known as a “bot herder,” who controls the compromised devices and sends them commands. These commands can range from distributing spam to launching distributed denial-of-service (DDoS) attacks or even hacking into the victims’ personal devices.
Infections occur through various means, including phishing emails, software vulnerabilities, or exploitation of default credentials on IoT devices like routers and cameras. Once infected, devices join the botnet as zombies and can be controlled remotely by the bot herder.
At their peak, some of the largest botnets in history have comprised millions of compromised devices. Some examples include the Conficker worm, which infected 15 million Windows systems, the Cutwail botnet that sent over 74 billion spam messages, and the Mirai botnet, which targeted Internet of Things devices with default or weak credentials and led to DDoS attacks across North America and Europe.
Several signs of a botnet infection may include a computer or device acting sluggishly, taking longer than usual to open apps, or using more data than normal. It may also feel hot or overheat when performing tasks like cryptocurrency mining or spam delivery. Botnets can eat up your battery and processor power, and they can also drain your device’s energy by sending and receiving large amounts of data in the background without your knowledge. Identifying the command and control (C&C) servers can help close down botnets by cutting off their ability to communicate with infected machines.