Types of Botnet you should know to prevent cyber attacks

There are several types of botnet that cybersecurity professionals and website owners should understand. Each type operates with its own structure, communication method, and attack capability. By learning how these botnets function and the specific risks they pose, organizations can develop stronger strategies to detect, prevent, and mitigate potential attacks. 

>>> See more: What is a Botnet? Definition, examples, and prevention tips

How to classify BotnetsLink to heading

Classifying botnets can be complex because they can be analyzed from multiple perspectives. Security researchers often categorize them using several different factors, including:

• Botnet functionality or purpose
• Botnet architecture or structure
• The operating platforms they target (such as Windows, Linux, or others)
• How they are controlled (manually by an attacker or automatically through scripts)
• How they are developed (custom-built botnets or those created from ready-made kits)
• The specific malware installed within the botnet’s Trojan component
• The infection method used to compromise the victim’s device (for example through exploit kits, browser vulnerabilities, phishing emails, or spam campaigns)

Understanding these criteria helps cybersecurity professionals identify the types of botnet operating in the wild and better evaluate the risks they pose.

Functionality or purposeLink to heading

Most botnets are built to allow attackers to easily control and manage many compromised devices from a central location. In most cases, a single system known as a Command and Control server (C&C or C2) is used to send instructions to thousands of infected machines. Through this centralized control, attackers can coordinate large-scale activities without directly interacting with each device. 

Understanding these operational models is important when studying the different types of botnet and how they are used in cybercrime.

Botnets can perform a wide variety of malicious tasks once devices become infected. For example, attackers may take control of a victim’s computer, collect sensitive information stored on the device, or monitor user behavior. Some botnets record keystrokes, capture screenshots, or track browsing activity to gather valuable data.

Others are used to send massive volumes of spam emails or to launch distributed denial-of-service (DDoS) attacks against targeted systems. Based on their primary functionality and control methods, several types of botnet can be identified.

Botnets that control a single infected computer, often referred to as a zombie, typically rely on the machine’s IP address for identification. In many cases, these botnets communicate through Internet Relay Chat (IRC) channels using specialized software clients. Bots themselves are small programs designed to automatically execute commands at specific times or when certain conditions are met. 

This category represents one of the simplest types of botnet to create and manage because it requires minimal infrastructure and may not even rely on a complex command server. Due to their simplicity, cybercriminals often use these botnets for activities such as sending spam emails, installing backdoors on victim machines, or participating in DDoS attacks.

Another common category involves botnets that control many infected computers through their IP addresses using Internet Relay Chat (IRC) as the communication platform. Over time, IRC has become one of the most widely used systems for botmasters to manage their networks of compromised devices. 

IRC-based botnets allow attackers to gather infected systems from different regions of the world and organize them into a single controllable network. These larger types of botnet make it easier for cybercriminals to coordinate attacks on a much broader scale.

To establish an IRC-based botnet, attackers first search for vulnerable devices that can be compromised. This discovery process often includes several technical methods such as:

• Port scanning
• Vulnerability scanning
• Exploit scanning

After identifying potential targets, attackers deploy various tools to compromise the systems. This often involves installing malicious software such as Trojan horses or backdoors, which may be delivered through exploit kits or other malware distribution techniques. Once the infection succeeds, the compromised machines become part of the botnet network. 

These types of botnet are typically spread across many countries and remain active at all times, allowing attackers to execute commands whenever needed. In many cases, they include specially designed Trojan programs created to steal financial information or conduct fraudulent activities against users worldwide.

Another group of botnets controls multiple infected computers using Remote Administration Tools (RATs). These tools are installed on victim devices to give attackers remote access and full administrative control. A RAT is essentially a software program that allows someone to operate one or more computers from a distant location. 

In malicious contexts, these programs are secretly installed on victims’ systems without their awareness. This method represents another important category among modern types of botnet.

RAT-based infections are commonly delivered through deceptive or malicious sources, including:

• Fake software update websites
• Trojan programs
• Spyware
• Keyloggers
• Other forms of malware

Once the attacker successfully installs a RAT on the target system, they gain extensive control over the machine. This access allows them to retrieve data from the device, upload additional malicious files, monitor user behavior, or perform many other unauthorized actions. 

Botnet operators typically manage these compromised devices by remotely installing additional modules and sending commands through networks such as Internet Relay Chat. This modular approach allows the botnet to expand its capabilities over time.

Another major category includes botnets designed specifically to launch distributed denial-of-service (DDoS) attacks. These networks coordinate large numbers of infected devices to overwhelm a target server, website, or network infrastructure with massive volumes of traffic. As with several other types of botnet, control commands are often delivered through IRC channels or similar communication systems.

When one bot within the network receives an instruction from the attacker, it begins sending traffic toward the target system. When thousands or even millions of compromised devices execute the same command simultaneously, the target infrastructure can quickly become overloaded and inaccessible. These DDoS-focused types of botnet are widely used in cybercrime because they can generate extremely powerful attacks.

In some underground communities, botnet operators even rent access to their networks through online forums or specialized services. This allows other attackers to launch DDoS campaigns without needing to build their own infrastructure. 

As a result, botnets have become a significant tool for cybercriminal operations, enabling anonymous attacks against websites, businesses, or online services while hiding the identity of the individuals responsible.

Architecture or structureLink to heading

Client-Server ModelLink to heading

The client–server model is one of the most widely used types of botnet. In this structure, a central command-and-control (C&C) server manages the entire network of compromised machines. The botmaster sends instructions to the C&C server, which then distributes those commands to infected devices. These instructions can include actions such as launching attacks, sending spam, or executing malicious tasks on the compromised systems.

Peer-to-Peer ModelLink to heading

Peer-to-peer (P2P) botnets represent another important category among types of botnet. In this design, each infected device can act as both a client and a server. Instead of relying on a single central server, nodes communicate directly with each other, often using protocols like IRC or HTTP. Because there is no single control point, this structure is more difficult for defenders to shut down, while attackers can still coordinate malicious activity across the network.

Controlled or Compliant ModelLink to heading

This architecture is derived from the client–server model but introduces a different control method. In this setup, attackers first compromise an existing server and install malicious software on it. The infected server then connects to a command-and-control system that assigns tasks to perform. Through this approach, attackers can disguise botnet activity by operating through hijacked infrastructure.

Hybrid ModelLink to heading

Many modern types of botnet combine elements from multiple architectures. Hybrid botnets often merge client–server and peer-to-peer mechanisms to increase flexibility and resilience. Some networks even incorporate aspects of all three models, making them harder to detect and dismantle while allowing attackers to maintain stronger control over infected devices.

Targeted platformsLink to heading

Windows-based botnetsLink to heading

Microsoft Windows remains one of the most frequently targeted platforms for malware infections and malicious bot programs. Its widespread global usage makes it highly attractive to cybercriminal groups seeking large numbers of compromised devices. In addition, the operating system has historically faced many security vulnerabilities, which attackers can exploit to build botnet networks. 

For this reason, running outdated Windows versions significantly increases the risk of infection and participation in botnet activity.

Linux-based botnetsLink to heading

Linux botnets commonly focus on two main targets: servers and personal systems. Because Linux powers a large portion of internet infrastructure, such as web servers, hosting environments, and file-sharing services, it provides valuable resources for attackers. As a result, the number of Linux-based bots has grown steadily. 

Linux is also embedded in many network devices, including home routers and IP cameras, which further expands the potential scale of these types of botnet.

Android-based botnetsLink to heading

Botnets targeting Android devices are relatively new but represent a rapidly developing threat. Security researchers have already discovered malicious Android programs, such as Trojan-SMS.AndroidOS.Opfake, that can turn mobile devices into controlled bots. As Android continues to dominate the global mobile market, these types of botnet are expected to become more common and more sophisticated.

Mobile botnets on other platformsLink to heading

Botnets targeting other mobile operating systems, including iOS or BlackBerry, may appear in the future. At present, however, they are less common because these platforms hold a smaller market share or maintain stronger application control systems compared to others.

The way Botnets are controlledLink to heading

Another way to understand the types of botnet is by looking at how they are controlled. The level of automation or human involvement determines how attackers operate these malicious networks.

Automated botnetsLink to heading

Automated botnets run independently without direct human supervision. After infecting devices, they automatically use system resources such as CPU power and network bandwidth to perform tasks ordered by the attacker, often including large-scale DDoS attacks. These bots are typically engineered to avoid detection, making them difficult for traditional antivirus tools to identify. 

Because they operate continuously and silently, automated systems remain one of the more persistent types of botnet used in cybercrime.

Manual botnetsLink to heading

Some attackers prefer complete control over their malicious infrastructure. In manual botnets, cybercriminals directly manage infected devices and decide when and how an attack is launched. This approach allows an attacker to trigger malicious actions from any compromised system at a chosen moment. 

Certain manual botnets can also download new versions of their malicious code from remote servers, allowing attackers to update capabilities and maintain control over time.

The way Botnets are builtLink to heading

Botnets can also be categorized by the way they are created and deployed. This classification reveals another important perspective on the different types of botnet operating on the internet.

Custom-built botnetsLink to heading

Some cybercriminals obtain botnets through specialized vendors who provide ready-made infrastructures containing large numbers of infected machines. These services allow attackers to quickly access a network of compromised devices without building one themselves. Many groups favor this model because it saves time and eliminates the need to manage the technical process of creating and maintaining their own botnet system.

Off-the-shelf or prebuilt botnetsLink to heading

A prebuilt botnet is already deployed and functioning before it reaches the attacker. Instead of purchasing permanent control over infected devices, users typically rent access to the botnet for a specific time period, such as a day or a week. This model is common in underground cybercrime markets because it offers flexibility and requires minimal effort from the attacker. 

The type of malware they useLink to heading

Different types of botnet are often classified by the malware that powers them. Cybercriminals use a variety of malicious programs to infect devices, control them remotely, and perform specific tasks within a botnet network. The most common examples include the following:

DDoS botnetsLink to heading

These botnets rely on large numbers of infected computers to generate massive traffic and overwhelm a chosen target. By controlling hundreds or even thousands of compromised devices, attackers can launch powerful distributed denial-of-service attacks that disrupt websites or online services. In many cases, operators of these botnets rent them out to other criminals who want to carry out attacks without building their own infrastructure.

Network-probing botnetsLink to heading

In this model, infected machines are mainly used to scan the internet and locate vulnerable systems. Once weaknesses are discovered, the botnet attempts to infect those devices with malware and convert them into additional bots. These types of botnet are often directed toward valuable targets such as servers. 

The goal is to gain complete control of the system, including its data, software, and hardware resources. A botnet may become extremely powerful once it successfully compromises even one high-performance server, especially in sectors like finance, defense, or energy.

Backdoor botnetsLink to heading

Backdoor botnets use infected computers as entry points to compromise additional systems. Each compromised machine helps spread the malware further, expanding the network of devices that attackers can control remotely. Over time, the attacker builds a larger botnet capable of performing coordinated malicious activities.

Information-stealing botnetsLink to heading

Some types of botnet focus on collecting sensitive data from infected systems. Malware installed on victims’ devices may record keystrokes, capture screenshots, or monitor user activity. The stolen information such as login credentials or financial details, is then sent to a remote server controlled by the attacker or sold on underground markets. 

These infections may occur through social engineering, where victims are tricked into installing malicious software, or through automated methods like drive-by downloads. Trojans, worms, and other password-stealing malware are commonly used in these botnets.

Spam-sending botnetsLink to heading

Although spam is sometimes viewed as an old problem, it still exists on a massive scale. Spam botnets distribute huge volumes of unsolicited messages from infected computers worldwide. Email addresses may be collected from public websites or harvested through infected machines. In some cases, botnets built from compromised devices such as routers, printers, or IP cameras are also used to send spam. 

By spreading messages across many systems, attackers make their campaigns harder to detect and block.

The way botnets infect a victim’s deviceLink to heading

Based on how a device becomes compromised, cybersecurity experts classify several types of botnet according to their infection and control structure.

Centralized botnetsLink to heading

Centralized botnets operate through a single command-and-control server, often called a C&C server. This server acts as the main hub where the attacker sends instructions to all infected devices. Once malware is installed on a victim’s machine, the device connects to the C&C server to receive commands. These instructions may include sending spam emails, distributing malware, or participating in large-scale DDoS attacks. 

A centralized network can control tens of thousands of infected devices, commonly known as bots. Among the different types of botnet, this model is relatively easier to disrupt because security teams can disable the entire network by identifying and shutting down the central server.

Decentralized botnetsLink to heading

Decentralized botnets, often referred to as peer-to-peer botnets, operate without a central command server. Instead, each infected device shares the same malicious code and communicates with other bots in the network. Even if one device is removed or blocked, the remaining machines continue operating and distributing commands among themselves. 

These types of botnet usually consist of hundreds of compromised devices and are significantly harder to detect or eliminate. Because control is distributed across many nodes, shutting down one component does not stop the network. This resilient structure makes decentralized botnets increasingly attractive to attackers who want a powerful and difficult-to-dismantle attack network.

Stop Botnet attacks with W7SFWLink to heading

For website owners, preventing botnet-related threats should be a top security priority. Many types of botnet actively scan the internet to find vulnerable websites, especially WordPress sites that lack proper protection. Once attackers identify a weakness, they can exploit it to inject malware, launch spam campaigns, or even use the compromised website as part of a larger attack network. 

This is why having a strong firewall layer is essential for blocking malicious traffic before it reaches your site.

W7SFW - WordPress Firewall is designed to help protect WordPress websites from these evolving threats. The firewall continuously monitors incoming traffic, blocks suspicious requests, and prevents unauthorized access attempts that could lead to malware infections or botnet activity. 

If you are running a WordPress website, activating W7SFW is a practical step to strengthen your security defenses. 

ConclusionLink to heading

Understanding the different types of botnet is essential for anyone responsible for managing websites, servers, or digital infrastructure. Botnets can vary widely in their architecture, control mechanisms, targeted platforms, and malicious purposes.  

By learning how these botnets are created, how they infect devices, and the types of malware they rely on, security teams and website owners can better recognize suspicious activity and reduce potential risks.