What is a Botnet? Its Types, & How to Protect Against It?

Professionals who are associated with system security arrangements must be familiar with the term botnets. It’s short for ‘robot network’, often used for the chain of hijacked systems. Today, we’ll discuss what a botnet is, its nature, how it works, how hackers control it, and what you can do to protect yourself from it. So, without further ado let’s start with the definition.

Botnet Definition – Understand Its Nature

Botnets are groups of compromised machines that are used in a variety of online scams and attacks. The words “robot” and “network” are combined to form the term “botnet”. Typically, the infiltration stage of a multi-layer approach is when a botnet is put together. 

But, What are botnets used for?

Well, they are used to automate significant attacks, such as the spread of malware, server failures, and data theft. Also, botnets utilize devices to disrupt normal operations or swindle other individuals without their knowledge or permission. 

You can say the main motive for creating botnets is to lure people in different ways such as Financial theft, Information Theft, Sabotage of Services, Cryptocurrency scams, Selling access to other cybercriminals, etc.

Different Types of Botnet Attacks

There are different kinds of botnets present and they have their own set of characteristics. Mostly, they are used for fulfilling malicious purposes. 

1. Botmaster – It is an individual system that runs command and control of botnets.

2. Zombie Computer – The 2nd type of botnet is a machine that’s connected to the internet and is directly controlled by a hacker.

3. Spambot – It’s a type of botnet that distributes spam emails to other devices.

4. Spyware –  This botnet is used for automatically clicking on links for online advertising or on web pages.

5. Dial-up Bots – This type of botnet is losing its popularity. However, it was one of the famous botnet attacks where it forced the user to switch numbers.

6. Credential Stuffing – Through this, botnets automate the process of trying a large number of username-password combinations on various online services

7. Click Fraud – For generating revenue, cybercriminals created botnets that can be employed to simulate clicks on online ads.

8. Ad Fraud – Just like the above, Ad fraud is a type of botnet that ​​can mimic human behavior to generate fake interactions with online ads

How Does a Botnet Work?

This method involves several steps. When fully utilized, botnets have the ability to carry out massive-scale attacks. To increase a botnet’s functionality, hackers must maintain it with additional tools or equipment. The key terms must be understood in order to gain a greater grasp of botnets’ mode of operation.

A bot herder is needed to lead the network’s connected infected devices. It is operational by remote commands and directs the devices to carry out specific tasks.

[Image Source: Sectigo]

To understand the functionality, it’s important to understand the botnet-building process. Let’s have a look at the 3 stages of botnet-building. 

Stage – 1

It’s the prepare and expose stage. Here, the hacker finds out the vulnerability to sneak into the user’s device.

The search for vulnerabilities involves looking at the website, people, and applications. By doing this, the hacker creates a setup that will entice the target to unwittingly or consciously expose themselves to malware.

Hackers frequently discover weaknesses in software and websites. And, Malware can also be sent by email or chance messaging.

Stage – 2

It’s the stage where hackers infect the user’s device using malware. The botnet’s next activity is to activate the malware, which renders the end-user vulnerable and infected. Trojan viruses or social engineering techniques are typically used to infect the device.

Some attackers use drive-by-download methods to infect the device in a more aggressive manner. Attackers infect the targeted device with botnet software using any of these techniques.

Stage – 3

In the last stage, the botnets try and control the targeted devices. The involved infected devices in the botnet are organized by hackers who also devise a means for controlling them remotely. Thousands of devices are often controlled in the process via a vast zombie network. Once the stage is finished successfully, the malicious party is able to access the targeted computers or devices with administrative privileges.

Hackers were able to access or write anything stored in the system, acquire any personal information, share data from targeted devices, monitor all activity taking place on the targeted device, and hunt for other hidden weaknesses thanks to the successful activation of the botnet.

Different Ways the Botnets are Controlled

Botnets can be controlled in two ways.

One of two models, a decentralized system with numerous links connecting all the infected botnet devices, or a centralized model with direct communication between the bot herder and each computer, is how to bot herders manage their botnets.

1. Centralized Client-Server Model

One command-and-control (C&C) server controls the whole botnet in the client-server architecture of the first generation of botnets. The drawback of utilizing a centralized approach over a P2P model is that it is more prone to a single point of failure due to its simplicity.

IRC and HTTP are the two most popular channels for C&C communications:

Botnet for Internet Relay Chat (IRC)

IRC botnets are among the oldest varieties of botnets and are managed remotely using an IRC server and channel that has already been set up. The bots establish a connection to the IRC server and await orders from the bot herder.

HTTP botnet

An example of a web-based botnet is an HTTP botnet, in which the bot herder transmits commands using the HTTP protocol. Bots will periodically check the server to download new commands and updates. The herder can hide their activity by passing off HTTP protocol as regular web traffic.

2. Decentralized, Peer-to-Peer Model

Peer-to-peer botnets, which do not directly communicate with the C&C server, allow bots to communicate with each other and share information and commands.

Because they don’t depend on a single centralized server, P2P botnets are more difficult to set up than IRC or HTTP botnets but also more resilient. Instead, every bot functions independently as both a client and a server, updating and exchanging data in a coordinated manner among the botnet’s machines.

How to Detect Botnet on Your Computer?

Botnets are designed to go undetected. However, if you pay close attention to your computer’s behavior, you will notice some clues or symptoms. Through this, you’ll be able to detect their presence in your device.

First thing first, if you know how a botnet works, half a thing is done which is already covered in the previous section. 

Secondly, observe any atypical behavior. It is important to monitor your sent folder or personal network, as people may reach out to you regarding suspicious emails you have sent with links in them. This unusual activity may not be due to email spoofing or the need to change your password. It is possible that a botnet has been downloaded onto one of your devices, which is causing it to send out emails with the intention of installing Trojan horses on other devices.

How Do You Protect Against Botnet?

We advise your business to take into account the following suggestions to stop your devices from joining a botnet:

• A regular cyber security training course that instructs users and staff on how to spot dangerous connections.
• To lessen the likelihood that a botnet assault will take advantage of system vulnerabilities, keep your software updated at all times.
• If a password has been hacked, use two-factor authentication to stop botnet software from accessing devices and accounts.
• Change the passwords on all of your gadgets, paying specific attention to the privacy and security settings on those that link to the internet or other devices or devices.
• Opt for a reliable SOC and NOC center that periodically scans the network and is kept up to date.
• Install a network-wide intrusion detection system (IDS).
• A rootkit detection capability endpoint security solution with the capacity to identify and stop malicious network traffic.

If you are ready to take the next step and want to secure your organization’s IT assets, contact our cyber experts now!

Even Govt. of India is running a campaign to make citizens aware of botnets. You can have a look at the screenshots below for reference.

FAQs

Q. What is a bot?

A bot is simply a software program that runs on the internet to carry out automated tasks. It can mimic human activity such as messaging, on a large scale. Though it was designed to simplify human tasks and save time, some individuals use it with malicious intentions. 

Q. What is a botnet in cyber security?

A botnet is a group of computers or a network of computers that have been infected to fulfill the attacker’s goal. 

Q. What is a brute force attack & is it related to a botnet?

Yes, this attack uses a botnet to guess the correct combination of usernames, passwords, and other authentication details to gain unauthorized access. 

Q. Who is a bot coordinator?

It can be an individual or a group responsible for managing botnets that are further responsible for launching DDoS attacks, stealing data, and spreading malware.