What Is a Botnet?

A botnet is a network of infected devices known as bots, which are controlled by a single attacking party known as a bot herder. Botnets are made up of Internet of Things (IoT) devices such as computers, mobile devices, network routers and smart TVs. 

Botnets are used to carry out time-consuming cyber activities such as managing online chatrooms or tracking internal data. However, cybercriminals can use botnets for malicious purposes such as launching large-scale cyber attacks and stealing sensitive data.

Continue reading to learn more about botnets, how they work, how they are used, the types of botnet attacks and how to avoid becoming part of a botnet.

How Botnets Work

Cybercriminals need to infect and collect as many bots as they can to build a botnet. They use social engineering tactics to trick users into installing malware on their devices which gives them total control over the device. Once the device has joined the cybercriminal’s botnet, they can send the botnet commands to carry out their malicious activity.

To build a botnet, cybercriminals need to:

• Expose the device: Hackers look for security vulnerabilities in a website, application or human behavior to install malware on a device and gain unauthorized access. They will try to determine which social engineering tactics or cyber threats they can use to exploit these vulnerabilities and help them gain access without detection.
• Infect the device: Once hackers find the security vulnerabilities, they will try to infect the device undetected and install malware using methods such as exploit kits, phishing and malicious advertisements. They often use Trojan horses to infiltrate devices and secretly install malware while appearing as legitimate software.
• Activate the device: Once the malware has infected the device, the cybercriminal has total control over the device and can send it commands to carry out malicious activity. The botnet can grow and infect other devices or launch cyber attacks.

How Are Botnets Controlled?

With so many devices connected within a botnet, bot herders use two models to control bots and send them commands: centralized and decentralized models. Here is a closer look at each model.

Centralized

With a centralized model, cybercriminals directly communicate with each bot using one Command-and-Control (C&C) server. Cybercriminals use their C&C server to control all of the connected bots at once. However, centralized botnets are easily discoverable and susceptible to a single point of failure. If the C&C server is compromised, then the cybercriminal loses contact with their bots.

Decentralized

With the decentralized or peer-to-peer model, cybercriminals control the botnet by sending the command to one of the connected bots instead of a C&C server. When one of the bots gets the command, the bot shares the command with the other bots within the botnet. Each bot continues to share the command until all of the bots receive it. The peer-to-peer model makes it difficult to identify bot herders and disrupt their control over their bots.

What Are Botnets Used For?

Although botnets were not originally created for malicious purposes, cybercriminals take advantage of botnets and use them for personal gain. Here are the ways cybercriminals use botnets.

Steal sensitive data

Cybercriminals will use botnets to launch cyber attacks that try to steal sensitive data from a user or organization. Cybercriminals can use botnets to compromise passwords, gain access to a system or device, and steal any sensitive data such as financial information, credentials for privileged accounts and personally identifiable information.

Deliver malware

Botnets try to self-replicate and add more bots to their network. Cybercriminals can use botnets to find devices that have security vulnerabilities and deliver malware to those devices. Once infected, cybercriminals can either add it to their botnet or steal sensitive data from the device.

Extortion

Cybercriminals can use botnets to launch large-scale cyber attacks on organizations and commit cyber extortion. Cyber extortion is when a cybercriminal digitally forces or coerces any entity to do something against their will. Cybercriminals will use botnets to compromise an organization’s valuable assets such as their sensitive data or access to servers. They only return access to those assets after the organization pays a ransom.

Generate fake internet traffic

Since each bot has a unique IP address, a bot can generate fake internet traffic. Fake internet traffic can be used to commit ad fraud in which cybercriminals use bots to click on ads that earn revenue for their malicious websites. Cybercriminals can also use fake internet traffic to slow down or crash an organization’s servers.

Types of Botnet Attacks

Here are the types of cyber attacks cybercriminals can execute using botnets.

Phishing attacks

Cybercriminals can use botnets to launch mass phishing attacks via email or other channels, spread malware, compromise devices and steal sensitive data. Phishing is a type of social engineering attack in which cybercriminals send messages to trick users into giving up their personal information. These messages contain malicious attachments or links for users to click on. 

When a user clicks on the link, they either download malware on their device or are taken to a spoofed website. On the spoofed website, they are prompted to give up their personal information such as their login credentials. 

DDoS attacks

Servers have limited bandwidth and can handle a limited number of requests. To obstruct an organization’s normal operations, cybercriminals launch DDoS attacks to gain money or damage the organization’s reputation. 

A Distributed Denial-of-Service (DDoS) attack is a type of cyber attack in which cybercriminals disrupt the normal traffic of a targeted server. Cybercriminals use botnets to overwhelm servers with a flood of internet traffic, which slows down or crashes the server.

Brute force attacks

Brute force attacks are a type of cyber attack that uses trial and error to guess a user’s login credentials until it gets a match. These types of attacks try to exploit users who have weak passwords that are reused, short or easily predictable. Cybercriminals can use a botnet to run programs that execute brute force attacks. With more programs executing brute force attacks, cybercriminals improve their chance of cracking a user’s password.

How To Avoid Becoming Part of a Botnet

Cybercriminals target devices vulnerable to cyber attacks that try to infect them with malware and give cybercriminals control over them. However, you can protect your devices from cybercriminals and prevent them from joining a botnet by practicing the following.

Use strong and unique passwords

To avoid becoming part of a botnet, you need to protect your devices with strong and unique passwords. Using a strong and unique password to access your device makes it difficult for cybercriminals to crack your password and gain unauthorized access. 

Strong passwords are a unique and random combination of uppercase and lowercase letters, numbers and special characters that are at least 16 characters long. It omits any personal information, sequential numbers or letters, and commonly used dictionary words.

Avoid clicking on suspicious attachments or links

Cybercriminals will try to infect your device with malware to turn it into a bot. They typically try to trick you into accidentally installing malware by sending you phishing emails or hiding them in Trojans. You should avoid clicking on suspicious attachments or links from unsolicited messages to prevent malware from infecting your device. Don’t download software from unreliable sources like suspicious websites or malicious advertisements.

Keep your software up to date

Cybercriminals will try to find and exploit security vulnerabilities to install malware and gain access to your device. Many security vulnerabilities are found in outdated software. You should keep your software up to date to patch security flaws and add security features that better protect your device.

Install antivirus software

Antivirus software is a program that prevents, detects and removes known malware from your device. It will detect any incoming malware and prevent it from infecting your device. With antivirus software, you can protect your device from malware that would give a cybercriminal total control over your device. 

Use Keeper® To Stay Protected From Botnets

One of the best ways to protect your device from joining a cybercriminal’s botnet is to use strong passwords to access your devices. To generate strong passwords, you can use a password manager’s built-in password generator. 

A password manager is a tool that securely stores and manages your personal information in a digitally encrypted vault. With a password manager, you can safely store and access your login credentials for your devices. A password manager will also identify weak passwords and help you strengthen them.

Keeper Password Manager uses zero-trust and zero-knowledge encryption to protect your login credentials. This ensures that only you have access to your password vault, which can only be accessed with your master password. Sign up for a free trial of Keeper Password Manager to protect your device from becoming part of a cybercriminal’s botnet.