Botnet attacks are one of the most serious cybersecurity threats today. These types of attacks usually occur as a result of malware infecting many computers, and hackers manage this attack from a single control center. Botnets can consume the network resources of target systems, leading to service interruptions, data theft, or even complete crashes. So what actually are botnet attacks? How can you detect such malware on your device? And how can you avoid being infected?

What Is a Botnet Attack?

Botnet attacks happen when a cybercriminal controls hundreds or even thousands of devices that have previously been infected with malware. These devices, managed by the hacker, attack a target system. Although there is only one computer that initiates it, the actual attacking devices are computers belonging to innocent people.

Diagram describing the attack of computers used as botnets

Suppose you find a free version of a game you're interested in online. You download it. But nobody cracks the free version of a high-paid game so that everyone can download it with no consequences. If a service is free, it's too good to be true in most cases. This file is very likely prepared by a malicious attacker. The attacker injects malware into it. When you download this innocent-looking game file, you actually infect your device with malware. If this file were posted on a forum with thousands of visitors, you can imagine how many people would download it.

Now, your computer is part of a botnet and the malicious attacker can control any device that joins this botnet at any time.

Of course, there are numerous ways you can be infected with malware, not only through cracked files. A file that comes in as an email, an unknown link, or a website you visit can infect your computer with malicious software. This may seem quite innocent because it is not yet active. During any attack, the malware activates and becomes a part of this attack, so your computer may be attacking somewhere without your knowledge.

Threats to a malware-infected computer that has joined a botnet are not limited to this. Attackers can also use it to threaten you, or indeed anyone. Botnets can affect bank employees, government officials, public servants, operators who make high money transfers, or any individual. The attacker makes victims' devices part of a botnet and may also demand a ransom, a confidential document, login credentials, and other important data.

How to Detect Botnet Attacks

cybersecurity expert who analyzes a botnet

Botnets reach and damage thousands of different computers every day, which makes preventing and detecting botnet attacks a very important security issue. Early detection of botnets plays a crucial role in hazard management as it will minimize damage. However, since botnets are made up of very light and harmless-looking malware, they consume little of your computer's hardware power. This makes it difficult to tell if there is a botnet on your system.

In some cases, slowing down or constantly crashing your internet connection can be a sign of a botnet presence on your system. If there is no change in your data usage, a slowdown in your internet connection may be a botnet red flag. However, a slow internet connection can occur for many different reasons, so that issue alone does not indicate that your computer is infected. A decent way to check is to look into your bandwidth. Excessive bandwidth consumption occurs if the attacker uses the botnet to carry out Distributed Denial of Service (DDoS) attacks and send spam emails. This causes a sudden drop in the internet connection of your device, which might mean you're affected by malware.

But the best way is to use your virus scanner. Antivirus software can effortlessly scan for botnets and other malware. Some antivirus software even uses a special botnet checker.

Finally, botnets make unexpected changes to your system files. If you detect such a change in your files or a corruption in your account configuration settings, you may suspect a botnet. Also, botnets infect your system files to prevent you from updating your operating system. You can see if a process you don't recognize is running by checking your Task Manager.

How to Avoid Botnet Infections

A computer screen protected from botnet

The malicious attacker controlling botnets can execute remote code and cause serious damage to your system. Botnets are light and difficult to spot—but not impossible.

Your priority should be ensuring your operating system is up-to-date. Never delay the update requests your operating system notifies you of. Almost every update package includes some security improvements.

When you want to download something to your device, make sure that the source you are downloading from is safe. When you search to download something, the attacker tries to lure you in with freebies and false promises; an attacker typically tries to trick you into clicking a link or downloading a seemingly-innocent file. You should not download a program whose source you do not know. Use safe, popular download sites, or go for open-source software. Peer-to-peer (P2P) downloads are very risky as they contain many malicious attachments. If possible, do not engage with P2P downloads.

When you install a new device to your network, never use default passwords. In particular, devices such as webcams and modems come with default credentials. Be sure you change these logins. Using default passwords makes IoT botnet attacks, like via Mirai malware, easy.

Using a strong password reduces the risk of any malware attack. In particular, two-factor authentication makes your accounts more secure. Make sure you read and configure the security protocols and security settings of the applications you use too.

You should also use reliable antivirus software that can warn you about files you missed that might've infected your system. Using a firewall automatically blocks unsafe connections. This method is a surefire way to protect yourself from botnets and other malware. Sometimes, applications may ask you to turn off your firewall, but an original and well-constructed program will not ask you to deactivate security measures.

The Best Way to Protect Against a Botnet Attack

The best line of defense against powerful malicious attacks like botnets is actually you. It is ultimately up to you not to click on links that you do not trust, to use a firewall, to install your updates, and to use strong antivirus software and strong passwords. When you take these precautions and have an awareness of cybersecurity, you should be protected from many attacks.

If you're after stronger protection, or if you really care too much about your privacy, you should seriously consider the operating system, programs, and network connections you're using. Fortunately, the precautions you take against botnets also apply to other malware.