Botnet Attacks: Types, Detection, Prevention – Safeguarding Your Systems

TL;DR

• A botnet is a web of infected devices secretly controlled by hackers to launch large-scale operations, such as DDoS attacks, spam, phishing, and data theft.
• Botnet attacks are one of the biggest cybersecurity threats in 2025, with over 8 million DDoS attacks recorded in just the first half of the year.
• The main types of botnets include IRC, HTTP, P2P, IoT, mobile, crypto mining, and cloud botnets.
• Warning signs of infection include slow performance, unusual network activity, hacked accounts, and suspicious processes running in Task Manager.
• Prevention requires proactive security measures like strong passwords, multi-factor authentication, and advanced monitoring tools.

The Growing Danger of Botnet Attacks

Botnet attacks are one of the fastest-growing cybersecurity threats in 2025, with hackers finding ever more advanced ways to exploit internet-connected devices. What once started as simple disruptions has now evolved into highly sophisticated operations capable of crippling businesses worldwide.

In just the first half of 2025, over 8 million distributed denial-of-service (DDoS) attacks were recorded globally, many powered by botnets built from hacked IoT devices and routers. By hijacking vast networks of compromised systems, cybercriminals can now orchestrate large-scale strikes that disrupt services, steal sensitive data, and inflict devastating financial losses.

Understanding what a botnet attack is, the types that exist, and the red flags to watch for can be an important step in building stronger defenses and staying protected against a perpetually evolving scope of threats. 

What is a Botnet?

A botnet is a web of devices infected with malware and secretly controlled by a cybercriminal. These devices, often referred to as bots or zombies, can include personal laptops, smartphones, and Internet of Things (IoT) devices, such as routers, smart cameras, and cloud servers.

Once compromised, the devices in a botnet are linked together and follow the instructions of a central operator known as the bot herder. The owner of the device usually has no idea their system is being used, while in the background, it may be sending spam, stealing data, or participating in cyberattacks.

Botnets are dangerous because they enable attackers to launch operations on a scale that would be impossible with just one machine. Instead of one hacker trying to break into a system, thousands or even millions of infected devices can work together.

How Do Botnets Work?

Botnets operate by quietly taking control of vulnerable devices and linking them into a network that follows a hacker’s commands. The process usually involves the following stages:

1. Infection: The first step is spreading malware through phishing emails, malicious downloads, compromised websites, or unsecured IoT devices. Once the malware is installed, the device becomes part of the botnet without the owner even realizing it.
2. Connection to Command and Control (C2): Thereafter, the compromised device connects to a command and control server or, in some cases, a peer-to-peer network controlled by the attacker. This link allows the hacker, often called the bot herder, to send instructions to every infected device.
3. Coordination: With thousands of devices now under their control, attackers can coordinate them to act as a single, powerful system. This is what makes botnets so effective for large-scale operations.
4. Execution of Attacks: Finally, when the botnet is active, the attacker can instruct it to perform a variety of tasks like sending spam emails, launching DDoS attacks, or infecting new devices.

Types of Botnets

Botnets come in different forms, and each type is designed to work in its own way. Their structure determines how they are controlled and how difficult they are to detect or shut down.

1. IRC Botnets

These are the oldest and most well-known types of botnets. They are controlled using Internet Relay Chat (IRC) channels and are primarily used for launching Distributed Denial of Service (DDoS) attacks.

2. HTTP-Based Botnets

These botnets communicate using the same protocol as websites, i.e., Hypertext Transfer Protocol (HTTP). They can be challenging to detect as they use regular web traffic for communication and can bypass firewalls and other security measures.

3. P2P Botnets

Peer-to-peer (P2P) botnets are decentralized, meaning no single control point exists. Instead, the bots communicate with each other in a peer-to-peer fashion, making them difficult to detect and shut down.

4. IoT Botnets

These are among the most common botnets in operation in the 21st century. IoT botnets are built from insecure smart devices such as routers, cameras, and other connected gadgets. The Mirai botnet is a well-known example, responsible for some of the most prominent DDoS attacks (about 380,000 IoT devices in the network). With billions of IoT devices now in use, this threat continues to grow.

5. Mobile Botnets

With smartphones playing a major role in everyday life, attackers increasingly target mobile devices. Mobile botnets are created by infecting phones through malicious apps or links, allowing hackers to steal data or send premium-rate spam messages.

6. Crypto Mining Botnets

These botnets hijack the computing power of infected devices to mine cryptocurrency. While they may not disrupt systems directly, they slow down services and increase electricity costs.

7. Cloud Botnets

With an increasing number of businesses making the switch to cloud networks, cybercriminals exploit misconfigured cloud servers to build botnets that can scale quickly. Cloud botnets can launch powerful attacks in a very short time.

The Types of Botnet Attacks Used by Cybercriminals

Once hackers build a botnet, they can use it in many harmful ways. Some attacks are meant to crash websites, while others steal data or spread spam. Here are the most common botnet attacks:

1. DDoS Attacks

DDoS attacks leverage the number of devices in the botnet to send massive requests or payloads to overload a target server or website, rendering the service inaccessible to legitimate users. 

2. Spam Attacks

Most online spam attacks are performed by botnets, which can launch tens of billions of spam messages daily. Malware and phishing are frequently propagated through spam attacks.

3. Financial Data Breach

Certain botnets aim to steal sensitive and valuable information, such as credit card information, banking credentials, and other similar data. For instance, the Zeus botnet focuses on e-commerce, social media, and banking websites. Additionally, botnets can be tailored to attack particular high-value services and digital resources in data breaches and leaks.

4. Monitoring

Devices that have been compromised and added to a botnet can observe the user’s actions and search for passwords and financial information to send to the bot herder. The botnet can also search for vulnerabilities in other devices, websites, and networks to spread the malware and grow the botnet.

5. Phishing Attacks

Botnets launch large-scale phishing attacks, where cybercriminals send seemingly innocuous emails containing infected links with the intention of stealing private credentials to access sensitive data.

The number of recipients falling for email trickery increases when such attacks are conducted through botnets. Suspicious emails with links or attachments should not be interacted with.

6. Brute-Force Attacks 

Brute-force attacks are a common technique cybercriminals use to gain access to a targeted victim’s account or system by repeatedly guessing usernames and passwords. Hackers use botnets to carry out such attacks on a large scale, with the compromised devices working together to guess a wide range of possible combinations.

7. Targeted Intrusions

Cybercriminals often deploy botnets to carry out targeted intrusions that lead to data breaches. In these attacks, they compromise a specific entry point within a network, which then allows them to move deeper into the system and gain access to sensitive resources.

Multiple connection requests from the same IP address to a single server port can indicate a targeted intrusion. 

Causes of Botnet Attacks 

Botnet attacks continue to grow because of weak security practices and the increasing number of internet-connected devices. Some of the main reasons include:

• Unsecured IoT Devices: Smart gadgets like routers, security cameras, and smart home devices are often shipped with default passwords or poor security settings. Hackers take advantage of these weak points to add devices to botnets.
• Outdated Software: Outdated computers, smartphones and IoT devices are easy targets. Cyber criminals scan the internet for known vulnerabilities and quickly exploit them to spread botnet malware.
• Weak or Stolen Passwords: Simple and reused passwords make it easier for attackers to break into devices. Many botnets also use brute-force attacks to guess login credentials and expand their network.
• Cloud Misconfigurations: As businesses move to the cloud, poorly secured servers and misconfigured settings are being exploited by attackers to build powerful cloud-based botnets. 
• Use of AI by Cybercriminals: Attackers now use artificial intelligence and automation to spread botnet malware faster and avoid detection, making traditional security tools less effective.

How to Detect Botnet Attacks

If you remain vigilant, you can tell if your computer is part of a botnet attack. Here are signs to watch for:

1. You Cannot Update your Computer: If you cannot update your computer’s operating system or antivirus software, it could be a sign that your computer has been infected with botnet malware. Cybercriminals may block these updates to prevent their malware from being detected and removed.
2. Your Fan Operates Loudly Even When Idle: If your computer’s fan operates loudly when your computer is idle, it could be a sign that your computer is being used to carry out a botnet attack. However, it’s advisable to ensure that no software updates are installed in the background and that your computer fan is clean before jumping to this conclusion.
3. Programs are Unusually Slow: If your computer’s programs are running unusually slow, it could be a sign that malicious programs are using the majority of your computer’s processing bandwidth. However, this could also indicate that your computer requires urgent maintenance.
4. Your Computer Shuts Down Very Slowly: Botnet malware may prevent your computer from shutting down at the usual speed to avoid interference with malicious background activities.
5. Your Email Account is Sending Unauthorized Messages: Botnet attacks can utilize your email account to propagate the infection to other machines. To avoid this, ensure that you log out of your email account after every session and don’t simply close the browser.
6. You Detected Suspicious Activity in Your Task Manager: Open Task Manager and look for unfamiliar programs that are consuming a lot of disk, CPU, or network resources. Consistently high usage by unknown processes can be a cue that your device has been infected with botnet malware. If you come across a process you don’t recognize, search its name online to confirm whether it is legitimate. If it appears suspicious, end the task immediately.

Steps to Take for Botnet Attack Prevention 

Preventing botnet attacks requires a proactive approach. Good security habits, regular updates, and the right tools can greatly reduce the chances of your devices being hijacked. Below are some of the most effective steps you can take to strengthen your defenses against botnet malware:

• Implement network segmentation to create a secure perimeter around vulnerable devices, especially IoT devices. That can prevent the spread of botnet attacks to other areas of your network.
• Regularly update all computer programs and IoT devices to fix any vulnerabilities that could be exploited by botnet malware or spyware. 
• Enable automatic updates for your web browser, operating system, and firmware to avoid missing critical security patches.
• Use antivirus software to detect and block botnet malware, and keep it updated to stay protected from the latest threats. Ensure your antivirus software works for mobile devices like Android and iOS.
• Install a firewall to detect and block botnet communications and prevent your resources from being used for cybercrime.
• Use strong login credentials and multi-factor authentication (MFA) across devices to keep cybercriminals from your private network. 
• Never interact with suspicious emails, links, or attachments. These are often used in phishing attacks to spread botnet malware. 
• Use a pop-up blocker to avoid accidentally downloading malware through advertising pop-ups. 
• Consider using an attack surface monitoring solution to detect any vulnerabilities in your ecosystem that could be exploited by botnet malware.

Takeaways

Botnet attacks have grown into one of the most dangerous challenges in cybersecurity today. They spread quietly, take advantage of weak devices, and can be used for everything from crashing websites to stealing sensitive data. What makes them even more concerning is how quickly they adapt, often staying hidden while causing damage a large scale.

At Imagine IT, we believe that for small businesses in the 21st century, staying protected cannot mean relying on basic anti-virus tools. Threats like botnets call for regular updates, strong access controls ,and expert monitoring to identify unusual activity before it turns into a crisis. 

With advanced cybersecurity solutions and proactive threat management, our specialists help businesses across the Midwest reduce risks and stay resilient against botnet attacks. 

Contact us today to learn how.

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Frequently Asked Questions (FAQs)

Q1. What is a botnet attack?

Ans. A botnet attack happens when hackers take control of many internet-connected devices and use them together to launch large-scale cyberattacks.

Q2. What are the common types of botnets?

Ans. The common types of botnets include IRC, HTTP, and P2,P with modern variants such as IoT, mobile, crypto mining, and cloud botnets.

Q3. How can I tell if my device is part of a botnet?

Ans. Warning signs include unusually slow performance, frequent crashes, high network or CPU usage, and accounts sending messages without your knowledge.

Q4. Why are botnets so difficult to detect?

Ans. Botnets hide by using normal internet traffic patterns, encryption, and even AI to mimic legitimate behaviour, making them hard to identify with traditional tools.

Q5. What is a real-life example of a botnet attack?

Ans. A famous botnet attack example is the Mirai botnet in 2016, which hijacked thousands of IoT devices, including cameras and routers, to launch one of the largest DDoS attacks in history. More recently, new botnets have been discovered targeting cloud servers and mobile devices.

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