DDoS attacks and other forms of botnet attacks remain some of the biggest cybersecurity challenges that are often the most difficult to defend against. In 2020 and early 2021, the number of DDoS attacks is continuously increasing, and the number of active malicious botnets is also rapidly increasing to a very alarming number.
With that being said, in this guide, we are going to discuss effective botnet prevention methods to protect your website and network.
We won’t be able to successfully prevent botnet activities without first understanding what a botnet is and how it works. So, let us begin this guide by discussing the concept of the botnet itself.
What Is a Botnet?
Before anything else, it’s important to understand that a botnet is not the same thing as a bot or internet bot. The terms are indeed often used interchangeably with each other, but they are actually two different albeit connected things.
An internet bot is a program script or software that is designed to execute automated tasks over the internet. Googlebot, for example, is software owned by Google that will crawl and index this website and millions of other websites all over the world.
A botnet, on the other hand, refers to a group of devices that have been compromised by malware or other means, and are now under the control of a cybercriminal/hacker. A device that belongs to a botnet is called a zombie device, and the cybercriminal can now command these devices to perform various cyberattacks. A zombie device may or may not run a bot in carrying out the attack.
The cybercriminal controls the devices in the botnet by running a C&C (Command and Control) server and typically will use various techniques and technologies to mask the C&C server’s location and identity.
Different Types of Botnet Attacks
The cybercriminal controlling the botnet (often called a botnet herder), can command the botnet to launch various types of botnet attacks, including but not limited to:
- Distributed Denial of Service (DDoS) attack
- Bitcoin mining and other cryptocurrency-related attacks and frauds
- Perform brute force and credential stuffing attacks
- Damaging the host device with malware and ransomware
- Stealing information within the device (i.e. password, financial data, etc. )
- Send phishing attempts, spam, and viruses to other devices
Is Your Device a Part of a Botnet?
The cybercriminal/bot herder will do everything in their power to prevent the device’s owner from knowing that the device has been compromised. Thus, whether our devices have been compromised and turned into part of botnets can be very challenging to detect.
However, there are some symptoms that might help in detecting botnets:
- Devices run (significantly) slower than normal
- The fan suddenly starting up when the computer is sleeping/idle
- Error messages and unexpected pop-ups
- A sudden spike in traffic in port 1080 (used by proxy servers), port 6667 (used for IRC), and port 25.
- Slower internet speed or other issues with internet access
Effective Botnet Prevention Methods
When discussing “botnet prevention”, we actually need to consider two different things:
- Preventing our devices from being converted into parts of a botnet
- Preventing attacks launched by botnets to our system
With that being said, here are some effective prevention methods to try:
1. Use a Comprehensive Botnet Prevention Solution
In theory, the most effective approach to prevent botnet attacks is to identify and block activities from C&C servers, but it is very difficult and in some cases, impossible to do.
To effectively identify C&C servers, the botnet detection solution should be able to tap into the communications between the C&C server and the botnet devices, but theoretically, this is only possible for security solutions that are dedicated to protecting the C&C device itself.
A more practical approach is to monitor and block the botnet attacks themselves, but signature-based detection is no longer very effective and may produce high false positives. The right technology is crucial in differentiating the harmless legitimate traffic from the botnet-driven traffic and botnet attacks
A bot and botnet detection solution can analyze every request to your website and service while using machine learning techniques to determine in real-time whether the traffic is a botnet or a legitimate user.
2. Update Everything Regularly
Especially important to prevent your system from being turned into a botnet is to update your OS, software, and applications regularly. Ideally, updates should be applied as soon as they are available. Especially if the software update contains security fixes, then it should be applied immediately, or else we are risking hackers exploiting this unpatched vulnerability.
3. Avoid Phishing Attacks
A very common method of turning your device into a botnet is via phishing attacks. So, it’s important to educate yourself (and your employees) on common signs of phishing attacks and how to avoid them.
In general, do not click on any link or attachment in emails from unknown and suspicious senders. If you aren’t sure about the email’s sender and it appears to come from a legitimate company, call the company’s hotline or known phone number to confirm the request first.
4. Get an Adequate Antivirus Solution
Since most devices turned into botnets via malware infection, it’s very important to invest in an adequate antivirus/anti-malware solution, as well as a security firewall. Make sure to update the antivirus solution regularly.
5. Other Best Practices
Other effective botnet prevention methods include:
- Using secure and unique passwords for each account
- Disable unused ports
- Periodic system backup and wipe/restores
- Avoid downloads from file-sharing networks and P2P torrents
- Implement strong security and access request policies
Don’t underestimate the seriousness of botnet attacks: even at the moment, your website, application, and service might be targeted by various forms of botnet attacks, and so you’ll need to be proactive in implementing the botnet prevention methods to protect your digital assets and your device from being turned into a botnet.