A botnet is a network of computers infected with malware and controlled remotely by hackers. These compromised machines can be used to send spam, launch DDoS attacks, generate fake web traffic, serve ads, or extort payments from victims.
Botnets are a significant threat if you don’t have the proper protections in place. They can operate on a massive scale, making them a powerful tool for cybercriminals. Understanding how botnets are created and used is essential if you want to stay safe from them in 2024.
In this guide, we’ll explain how botnets work and provide practical steps to avoid becoming part of one. That said, for comprehensive protection against botnets, I recommend using an antivirus like Norton. Norton can detect and remove malware, including botnets, and offers a 60-day money-back guarantee.
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What Is a Botnet?
A botnet is a network of computers that have been infected with malware and are controlled remotely by hackers. These compromised devices can be used for a variety of malicious activities, often without the knowledge of their owners. Botnets can be leveraged to carry out large-scale cyberattacks and other nefarious actions, including:
- Sending spam. Botnets can distribute massive amounts of spam emails, which can contain phishing scams or malicious attachments.
- Conducting DDoS attacks. Distributed Denial of Service (DDoS) attacks overwhelm websites or online services with traffic, causing them to crash and become unavailable.
- Generating fake web traffic. By simulating real user traffic, botnets can inflate website visit numbers, misleading advertisers and skewing analytics.
- Serving ads. Hackers can use botnets to deliver unwanted advertisements to infected devices, generating revenue through ad impressions or clicks.
- Mining cryptocurrencies. Botnets can hijack the processing power of infected devices to mine cryptocurrencies like Bitcoin, benefiting the attackers financially.
- Distributing malware. Botnets can spread additional malware to other devices, further expanding the botnet or installing ransomware.
- Stealing data. Botnets can harvest sensitive information such as login credentials, financial data, and personal details from infected devices.
- Click fraud. By simulating clicks on online ads, botnets can generate fraudulent ad revenue for the attackers.
- Proxy services. Botnets can be used to anonymize the attacker’s internet traffic, making it harder to trace their activities.
- Extortion. Attackers can demand payment from users to remove their devices from the botnet or to cease malicious activities like DDoS attacks.
Understanding the capabilities of botnets is essential for defending against them. Comprehensive security measures, including regular updates and powerful antivirus software, are key to protecting your devices from becoming part of a botnet.
How Are Botnets Created?
Botnet attacks are orchestrated through a multi-step process that involves infecting devices, establishing control, and executing malicious activities. Below is a detailed breakdown of each stage.
Step 1. Infection
The first step in creating a botnet is compromising devices to make them join the network. This is usually done through:
- Phishing Emails: These emails contain malicious links or attachments that, when clicked, install malware on the recipient’s device. The malware then allows the device to be controlled remotely as part of the botnet.
- Exploiting Vulnerabilities: Attackers look for and exploit software flaws or outdated security measures. By taking advantage of these weaknesses, they gain unauthorized access and can install malware that connects the device to the botnet.
- Drive-By Downloads: Malware can be automatically downloaded and installed when a user visits a compromised website, often without any user interaction or knowledge. These downloads happen silently in the background, adding the device to the botnet as soon as the malicious software is executed.
Step 2. Command and Control (C&C)
Once infected, devices are connected to a Command and Control (C&C) server the attacker uses to issue commands. This can be managed in 2 ways:
- Centralized C&C: A single server directs all devices in the botnet, issuing commands and receiving data. This centralized control makes it easier for attackers to manage and coordinate the botnet’s activities efficiently. However, it also presents a single point of failure; if the server is discovered and taken down by cybersecurity experts, the entire botnet can be disrupted or dismantled.
- Decentralized C&C: This model uses peer-to-peer (P2P) networks, distributing control among multiple devices within the botnet. Each device can act as both a client and a server, sharing control and coordination tasks. This makes the botnet more resilient and harder to dismantle, as there is no single point of failure that can be targeted to disrupt the entire network.
Step 3. Execution
The final stage involves compromised devices executing the attacker’s commands, such as DDoS attacks, data theft, or spam and malware distribution.
Examples of Botnet Attacks
Below are some of the most notorious and nefarious examples of botnet attacks. Some of these botnets are still operating, and some have been successfully thwarted.
Volt Typhoon Botnet
The Volt Typhoon botnet, discovered in May 2023, was a sophisticated cyber campaign operated by Chinese state-sponsored hackers. It primarily targeted critical infrastructure in the US, including Guam and Hawaii, exploiting vulnerabilities in hundreds of small office/home office (SOHO) routers.
Volt Typhoon’s strategy involved leveraging these compromised routers to gain stealthy access to networks and exfiltrate data without detection. The attackers employed “living-off-the-land” techniques, using legitimate system tools to avoid triggering security alarms. This method allowed them to conduct extensive reconnaissance, credential harvesting, and data exfiltration.
Fortunately, the botnet was disrupted in January 2024. The US Department of Justice and cybersecurity agencies removed the malware from hundreds of infected routers and blocked their communications with the command-and-control servers.
Emotet/Heodo & Emotet/Heodo Resurgence
Emotet, also known as Heodo, is a notorious banking trojan that evolved into one of the most destructive botnets ever. Initially discovered in 2014, Emotet began as a banking trojan but later turned into a modular malware capable of delivering other payloads, including ransomware. It primarily spread through phishing emails containing malicious attachments or links.
In 2021, international law enforcement agencies coordinated a takedown of Emotet’s infrastructure, dismantling its servers and arresting key operators. However, by late 2021, Emotet was back. The revived botnet adopted new tactics, techniques, and procedures (TTPs) and used previously compromised systems to rebuild its network.
“New” Emotet used more sophisticated phishing campaigns and partnered with other malware operators to maximize its distribution and impact. At its peak, Emotet had infected hundreds of thousands of devices globally, causing extensive financial and data losses.
Mirai Botnet Variants
The Mirai botnet, first discovered in 2016, is a vast botnet of IoT devices, such as IP cameras and routers. The most notable DDoS attack launched through the Mirai botnet brought down major websites like Twitter, Netflix, and Reddit by overwhelming the DNS service provider Dyn.
Since its initial appearance, Mirai has spawned numerous variants, each introducing new features and targeting additional device types. These variants have continued to exploit vulnerabilities in IoT devices, often with enhanced capabilities for evading detection and increasing their attack potency. Notable Mirai variants include Okiru, Satori, and Masuta.
How to Protect Your Computer From Becoming Part of a Botnet
Botnets sound pretty scary, and the truth is they can be put to some seriously nefarious uses. But keeping your computer or device from being recruited by one is relatively simple. Here are a few tips that will keep you safe in 2024:
- Run regular antivirus scans. This is the best and most effective way to deal with any form of virus or malware, including botnet malware. A reputable antivirus will prevent most botnet malware from ever being installed on your computer, and will easily remove it if you’ve already been infected. Brands such as Norton and
Bitdefender are my most highly-recommended brands. - Never download attachments from email senders you don’t know. Be very careful about opening messages from senders you don’t recognize. If you do, absolutely never download any attachments until you can find out exactly what it is and who it’s from. You should also be wary of unexpected attachments — even from known senders — as their computers could be infected by a botnet and they could be unknowingly propagating the malware.
- Run regular software and operating system updates to patch vulnerabilities. Most trusted antivirus providers and operating systems will offer frequent updates and patches in order to protect against the latest vulnerabilities. It’s easy to ignore regular software updates, but they could be key to keeping you protected from malware.
- Avoid untrustworthy websites & ads. A common way bot masters trick you into downloading their malware is by placing intriguing ads or downloads in your path during web browsing. Avoid downloading free software from unfamiliar websites and don’t click on pop-up ads that promise to fix your computer. Interacting with these pages can often initiate malware installation on your device. Installing trusted anti-spyware software will also add an extra layer of protection.
Signs You May Have a Botnet on Your Device
Recognizing the signs of a botnet is crucial for taking swift action to protect your data and privacy. Botnets can operate stealthily, but there are some telltale signs that may indicate your device has been compromised.
Common signs of a botnet infection include:
- Unusual network activity. Unexpected spikes in network traffic can indicate that your device is communicating with a botnet command and control server.
- Slow performance. A significant slowdown in your device’s performance, such as sluggish response times or frequent freezing, can be a sign of malicious processes running in the background.
- High CPU or RAM usage. If your device’s CPU or RAM usage is consistently high, it could be due to botnet-related activities like cryptocurrency mining or DDoS attacks.
- Unexpected data transfers. Look for unusual patterns in data transfer, especially large volumes of data being sent to unknown or unauthorized locations. To do so, check Activity Monitor on your Mac by pressing the Space key while holding the Command key and searching for “activity monitor” in Spotlight search. In Windows, you can check Task Manager by pressing Ctrl + Shift + Esc at the same time.
- Frequent crashes. Unexpected crashes or restarts can be a symptom of malware interfering with your system.
- Unwanted ads and pop-ups. An increase in unwanted advertisements and pop-ups can indicate that ad-serving malware is present on your device.
- Unusual emails or messages. If your contacts receive spam emails or messages from your account, it may be a sign that your device is part of a botnet sending spam.
- Disabled security software. If your antivirus or other security software is suddenly disabled or cannot be updated, this could be a sign of a malware infection.
- Suspicious applications or processes. Open Activity Monitor on your Mac or Task Manager in Windows to view running processes. You should also check for suspicious apps by opening a Finder window and clicking Applications on your Mac, or by searching for Apps & Features in Windows.
Staying vigilant and recognizing these signs can help you detect a botnet infection early. For comprehensive protection and removal of botnets, I recommend Norton, which offers excellent malware detection and a 60-day money-back guarantee.
How to Fully Remove a Botnet From Your Device in 2024
Method 1: Use Antivirus Software
Using antivirus software is the easiest and most effective way to remove a botnet. I recommend Norton because of its excellent detection and removal capabilities.
- Download and install Norton. Visit Norton’s official website and download the antivirus software. Install it by following the on-screen instructions.
- Run a full system scan. Open Norton and select the option to run a full system scan. This will check your entire device for malware.
- Remove suspicious files and apps. Once the scan is complete, Norton will display any detected threats. Follow the prompts to remove or quarantine these files.
- Stay protected. Once the botnet is removed, you need to take steps to stay protected. For example, you should keep Norton installed and ensure features like Auto-Protect are enabled. Once done, as long as you’re careful online, you should be safe from getting botnets in the future.
Method 2: Manually Remove a Botnet
Manual removal can be effective if you know which files and applications are malicious. However I only recommend it if you’re an advanced user. Even then, you should run an antivirus scan after removing the botnet because you won’t know what other malware it installed on your device.
Follow these steps to manually clean your device:
- Identify and remove suspicious applications. Go through your installed programs and uninstall any that look unfamiliar or suspicious.
- Reset browser settings. Restore your web browser settings to their default state to remove any malicious extensions or changes made by the botnet.
- Check system files. Review system files and processes for anything out of the ordinary. Use online resources to verify the legitimacy of unfamiliar files.
Method 3: Perform a Factory Reset
A factory reset will erase all data and return your device to its original state, effectively removing any botnet. Here’s how to do it for different devices:
Windows
- Backup your data. Save important files to an external drive or cloud storage (only back up data you absolutely trust, as you don’t want to back up the malware).
- Go to settings. Open the Start menu and go to Settings > Windows Update > Advanced options > Recovery.
- Reset your PC. Click Reset PC and follow the prompts to perform a factory reset.
Mac
- Backup your data. Use Time Machine or another backup method to save your important files.
- Restart your Mac. Hold down Command (⌘) + R immediately after turning on your Mac to enter Recovery Mode.
- Reinstall macOS. In the macOS Utilities window, select Reinstall macOS and follow the instructions to complete the factory reset.
How to Stay Protected After Removing a Botnet
After removing a botnet, it’s important you take the appropriate measures to avoid getting infected again. Here’s what you need to do:
- Change all passwords. Update passwords for all your accounts. Use strong, unique passwords for each one. Consider using a password manager to generate and store complex passwords securely.
- Enable Two-Factor Authentication (2FA). Wherever possible, enable 2FA on your accounts. This adds an extra layer of security by requiring a second form of verification in addition to your password.
- Alert your financial institutions. Inform your bank and credit card companies about the potential compromise. Monitor your accounts closely for any unauthorized transactions and consider placing fraud alerts if necessary.
- Run data breach scans. Use services like Have I Been Pwned to check if your personal information has been involved in any data breaches. Take immediate action to secure any compromised accounts. You can also use an antivirus with data breach alerts to get immediate alerts (Norton is one example).
- Report suspicious apps. Report any suspicious apps or software to the relevant authorities or platforms. This helps prevent others from becoming victims.
- Keep software updated. Regularly update your operating system, applications, and antivirus software to protect against the latest threats. Some antiviruses (like TotalAV) can alert you when there are new updates for your operating system or applications.
- Be cautious with downloads. Only download apps and software from trusted sources. Avoid clicking on unknown links or attachments in emails and messages.
- Review app permissions. Periodically review the permissions granted to apps on your device. Revoke any unnecessary permissions that could compromise your privacy.
- Educate yourself. Stay informed about the latest cybersecurity threats and best practices.
By following these steps, you significantly reduce the risk of future botnet infections and protect your personal information.
Frequently Asked Questions
What exactly is a botnet?
A botnet is a network of computers infected with malware and controlled remotely by a hacker. These compromised devices are used for malicious activities such as sending spam, launching DDoS attacks, generating fake web traffic, and more. Protecting your device with reliable antivirus software can help prevent it from being compromised and added to a botnet.
How can I tell if my device is part of a botnet?
Signs of a botnet infection include unusual network activity, slow device performance, high CPU or RAM usage, frequent crashes, unwanted ads, and unknown programs running. Running a full system scan with an antivirus can help detect and remove botnet malware, ensuring your device stays secure.
What should I do if I suspect my device is part of a botnet?
If you suspect your device is infected, immediately run a full system scan with an antivirus. Remove any detected threats, change your passwords, update your software, and consider performing a factory reset if necessary. Keeping an antivirus active on your device can provide ongoing protection against future infections.
How can I protect my device from becoming part of a botnet in the future?
To protect your device, you should keep your software updated, use strong and unique passwords with two-factor authentication, avoid downloading from untrusted sources, be cautious with email attachments and links, and use antivirus software to regularly scan for threats. These steps will help secure your device from botnet infections.
How long do botnets last?
Botnets can last for different amounts of time. Some are discovered and shut down within a few days or weeks, but others can survive for years, constantly changing to avoid detection.
The lifespan of a botnet depends on how advanced its design is, how resourceful the people controlling it are, and how well cybersecurity teams around the world work together to bring it down. Some botnets keep updating their techniques and tools, making it hard to catch them using traditional methods.
How common are botnet attacks?
Botnet attacks happen very often and remain a major threat to online security. They are commonly used to overwhelm websites with traffic (DDoS attacks), send lots of spam emails, and carry out other cybercrimes. It’s really important to follow these tips to protect yourself from botnet attacks.
The high number of botnet attacks is due to the increasing number of devices connected to the internet, many of which do not have strong security. This makes it easy for cybercriminals to take over these devices and add them to their botnets, making these attacks more frequent and impactful.
