What is a Botnet?
A Botnet is a network of computers and internet-connected devices infected with malware, allowing a cybercriminal to control them remotely without the device owners’ knowledge or consent. These compromised systems, often referred to as bots or zombies, work together under the direction of the hacker to carry out a variety of malicious activities at scale. These can include launching distributed denial-of-service (DDoS) attacks, stealing sensitive information, and sending spam or participating in click fraud.
Once a device is infected, it communicates with the hacker’s command and control (C&C) server to receive instructions. From there, the bots perform tasks such as stealing data, deploying DDoS attacks, and spreading malware. Signs of a botnet infection can include sluggish system performance, frequent crashes, unexpected pop-ups and ads, and high CPU or memory usage without an obvious cause.
Infected systems may also begin sending and receiving data in the background, straining processors and batteries. This can lead to overheating and other issues.
Attackers create botnets for various reasons, from making time-consuming tasks easier to generating revenue from criminal activities like piracy, spamming, and DDoS attacks. Most often, however, they simply want to cause trouble and make things more difficult for others. Botnets are powerful because they can harness the computing power and bandwidth of many infected machines to execute multiple automated tasks simultaneously. This gives them the ability to quickly launch attacks at a massive scale. Until recently, most botnets used a client/server model that leveraged centralized servers to exert control over all of the bots. Newer botnets, however, have been designed using components of decentralized peer-to-peer filesharing. This makes them more resilient and harder to detect and disrupt.