Botnet

What is a Botnet?

A botnet (robot network) is a network of infected computers and devices connected in a coordinated fashion for malicious purposes. Each Internet-connected device in a botnet is called a bot. These bots are compromised with malware and controlled by a third party, called a botmaster or bot-herder. Individually, each bot has little impact. However, as a network of many devices controlled by an attacker, botnets are used to automate large-scale cyberattacks.

Botnet activity includes transmitting malicious software (malware), phishing campaigns, stealing data, distributed denial-of-service (DDoS) attacks, and other malicious activities. Typically, users are unaware that their computers are infected and under the control of a botmaster.

Originally, botnets were created as a tool with valid purposes in Internet relay chat (IRC) channels. Eventually, hackers exploited vulnerabilities in IRC networks and developed bots to perform malicious activities such as password theft, keystroke logging.

A botnet may also be known as a zombie network, a phrase used to describe compromised computers and devices acting like “zombies.”  The terms are often used interchangeably.

How a Botnet Works

How are botnets created? Well, it often starts with attackers targeting computers not safeguarded with firewalls or antivirus software. A botnet manipulator can take control of a computer in various ways, but the most common methods include exploiting software vulnerabilities, sending email attachments, and embedding malware in website hyperlinks, and offering free software downloads.

For example, parents looking for trustworthy spy apps for legitimate monitoring activities may unknowingly download a free app that contains malware that turns your computer into a bot.

Once the malware is executed, the infected internet-connected computer or device is a bot and joins the botnet. When the attacker has control of multiple devices, they use remote commands to simultaneously coordinate botnet activity according to their objectives.

What Are Botnets Used For?

Botnets are significant because they have become tools used by both hackers and organized crime to perform illegal activities online. For example, hackers use botnets to launch coordinated denial-of-service (DoS) attacks, while organized crime uses botnets as ways to spam, or send a phishing attack that is then used for identity theft.

Even more concerning is the industry that has sprung up around botnets, where bot herders build botnets specifically to “rent” to the highest bidder. Whether they send spam, adware/spyware, viruses, worms, or other malicious software, botnets can be used to perpetrate just about any type of cyberattack.

Botnet Examples

Some of the most notable botnet examples include:

How Do Hackers Control a Botnet?

Attackers control a botnet through remote programming, using a command-and-control (C&C) server that enables them to maintain control using a botnet program. The C&C server facilitates communication between the attacker and the bots. For example, the attacker can send malicious botnet commands to the bots, which then report back with any stolen data or information and receive new instructions. The botnet program automates the process of installing code on bots, allowing them to receive and execute commands and communicate with the server.

What is a Botnet Attack?

A botnet attack explained in simple terms is when a large number of bots – the computers and other devices infected with malware – are used to carry out cyberattacks. According to AVG, the most common botnet attacks include spam and phishing attacks, malware distribution, brute force attacks, and cryptojacking.

Types of Botnet Attacks

• Backdoor botnets
• Brute force attacks
• Cryptojacking
• Data breach
• DDoS attacks
• File-sharing botnets
• HTTP botnets
• IRC botnets
• Phishing/spam botnets
• Ransomware attacks
• Spyware installation

8 Ways to Protect Yourself From Botnets

Botnet security relies heavily on users being proactive about protecting devices and being cautious when dealing with links and downloads.

Here is how to protect yourself from botnets:

• Avoid opening email attachments without verifying it first.
• Configure firewalls for maximum protection.
• Don’t click on suspicious/unexpected email links.
• Enable browser protection against phishing and malware.
• Keep device operating systems updated.
• Scan all downloads before executing them.
• Update factory default settings on devices.
• Use reputable antivirus software.

The Bottom Line

The botnet definition refers to a network of infected computers and devices connected in a coordinated fashion for malicious purposes. Botnet activity includes transmitting malware, launching phishing campaigns, stealing sensitive data, and distributing DDoS attacks.

Unfortunately, it can be difficult for users to detect botnet infections, and most are unaware that their device is infected. To protect against botnets, users need to be proactive – ensure devices are updated, change factory settings on IoT devices, and use caution when opening email attachments or clicking links.

Experts also recommend scanning free software before installing and using a reputable antivirus software to improve botnet security.

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