Internet, Networking, & Security Antivirus 45 45 people found this article helpful What Is a Botnet? Has your computer become a zombie without your knowledge? by Andy O'Donnell Writer Andy O'Donnell, MA, is a former freelance contributor to Lifewire and a senior security engineer who is active in internet and network security. our editorial process Andy O'Donnell Updated on December 07, 2019 Antivirus Online Scams Social Media Scams Email Scams Phone & Texting Scams Tweet Share Email The term “botnet” comes from the phrase “robot network.” A bot is a kind of software application or script that has been programmed to perform repetitive tasks. Botnets refer to many internet-connected devices all performing some automated assignment. The infected computers are known as zombies. Sometimes, as in the case of internet relay chats, botnets are perfectly legal. But usually, the term botnet relates to illegal, nefarious activity. If a botnet gains access to your device, your computer becomes part of a large-scale malicious plan. Infected desktop computers aren't the only risk. Botnets can also infect and use laptops, servers, routers, smartphones, or any other network-equipped device to conduct their illegal activities. How Does My Computer Get Infected? Bill Hinton/Moment/Getty Images For your computer to become part of a botnet, a specific type of malware must infect it. A botnet malware infection is just like any other kind of malware infection, except the ramifications can be much bigger. Botnets are installed onto unsuspecting computers in various ways, including Trojan horse viruses. Users unwittingly infect their own systems by clicking on a malicious link or pop-up, or by downloading unsafe software that seems legitimate at first glance. This malware acts as a gateway into your computer, gathering your personal information and making your system part of a unified cybercrime effort. The botnet software sets up your computer up to receive instructions from a master control terminal operated by a cybercriminal group. Today’s sophisticated botnets can even reproduce themselves, seeking out and infecting other vulnerable devices automatically. Will I Know if My Computer Is Infected? Botnets aren’t always easy to detect. It used to be that sluggish computer performance and annoying pop-up ads meant your computer was infected. These days, most users are unaware that anything is wrong with their system. Most botnets have a small footprint and can mask themselves so they can infect as many users as possible. ISPs will sometimes notify a user if botnet traffic was detected from their device. How Do Cybercriminals Use Botnets? Cybercriminals use botnets for various purposes. They may use botnets to conduct phishing scams or to send spam. They sometimes rent out their botnets to other hackers who want to commit these cybercrimes. A botnet can also be used to collect personal information from the infected computers and use it to commit identity theft. Hackers use botnets to create DDoS attacks, which are attempts to disrupt a server’s regular operations by overwhelming it with a crushing amount of traffic. DDoS attacks can effectively shut down a company’s network and service and do irreparable harm to a business. These attacks work so well because the target of the attack likely can't withstand the network and resource load of 10,000-plus computers all trying to access it at one time. Botnet operators sometimes blackmail DDoS targets, telling them that if they pay them a fee, they'll halt the attack. Some desperate businesses will pay the blackmail fee just to get up and running again. How Do Botnets Grow? Cybercriminals use malware affiliate marketing programs to spread botnet malware to unsuspecting victims, paying upwards of $250 or more for every 1,000 "installs." The malware developer will then sell control of the botnets they created. The larger the block of "slave bots," the higher the price they will ask. How to Protect Yourself From Botnets While there is no way to completely safeguard your system from botnets, there are ways to greatly reduce the likelihood of infection. Get a Malware-Specific Scanner Virus scanners won't always find scareware, rogue malware, rootkits, and other types of malicious software. Consider a product such as Malwarebytes, which is known for finding malware that often evades traditional virus scanners. Get a "Second Opinion" Scanner Just as you'd seek a second opinion about your health, a second opinion malware scanner can find problems that were overlooked by another tool. Install a second malware scanner on your computer; you'll be surprised how many times one tool misses something another one catches. Look Out for Fake Antivirus Software As you search for good malware protection, beware of malicious software masquerading as a malware scanner or blocker. Thoroughly research any product you consider downloading onto your computer. Never install anything sent via e-mail or found in a pop-up box. These are often delivery methods for malware developers and malware affiliates. If you've cleaned a malware infection from your computer, consider a performing a full backup, wipe, and reload of your computer to ensure that the malware is gone.