How Botnets Operate
Whether it’s infected software, malware-laden computers or internet infrastructure hardware like routers and IoT gadgets, the threat of botnets is real. These nefarious networks of hijacked devices work under the direction of attackers, known as botmasters, to perform tasks such as spreading click fraud malware, stealing data from compromised computers or launching cyber attacks against other networks. Understanding how these nefarious networks operate can help you better detect and mitigate them.
The first step in constructing a botnet is infecting devices with malware, allowing attackers to control them remotely without the device owner’s knowledge or consent. This can be done by exploiting vulnerabilities in software, phishing emails, cracking default credentials on hardware devices or even by using automated scanning tools to identify potential targets. Once a device is infected, it will then self-propagate the malware to recruit more devices into the botnet.
Once a botnet has been recruited, it will then wait for instructions from its bot herder via a command-and-control server. These servers can range from a single computer to the centralized approach where responsibility for giving out instructions is embedded across all the zombie computers (bots). While centralized botnets are still common, there’s been a movement towards decentralized models that are harder to shut down.
Once the botnet receives instructions from its C&C server, it will begin to execute its intended malicious activities. This can include a DDoS attack where the botnet floods target servers with traffic, stealing sensitive information or taking websites and services offline.