What is a Botnet?
A botnet is a network of physical devices that are connected to the internet and controlled by malware, leaving the owner of the device unbeknownst of anything. Devices may include computers, smartphones, web servers, smart gadgets, and almost anything connected to the internet. A botnet isn't intrinsically malicious. Botnets are capable of doing a variety of repetitive activities. By gaining access to additional materials from users, they can help develop bots, simplify, and accelerate the speed of operations.
However, since cybercriminals frequently exploit botnet techniques for nefarious objectives, the phrase does have a bad meaning. Harmful botnets are created as a result of malware transmission.
What does Botnet Mean?
Botnet attack is generally made by the attacker group known as
bot-herder. The system under attack by the bot-header is known as a
bot. The attacker takes control of the machine and spreads viruses, worms, and malware to the affected system. However, the bot is not only used for distributing malware but also to initiate distributed attacks from different places to a specific target.
Figure 1. What is Botnet
The term botnet is coined from two words robot and network. A botnet can cause network equipment to go offline if the network security does not match the standard protocol. The system could face cyber attacks like distributed denial-of-service attacks (DDoS) from botnets.
Botnets are among the most complex methods of contemporary viruses, posing a significant potential threat to authorities, businesses, and consumers. Botnets are highly organized, connected programs that utilize connections to develop strength and resistance, while the prior virus was a cluster of autonomous requests that merely attacked and duplicated oneself. A bot and botnet, rather than only a maliciously crafted application, is rather like getting a hostile attacker within your system since the systems are in threat of the bot-herder.
How Does Botnet Work?
A user can be a victim of a botnet attack if the attacker can manage to trick the user to install. Also, the attack could happen due to security vulnerabilities. Usually, attackers scan for the unpatched and outdated software, or equipment as an easy target. Due to the lack of security measures, a botnet can affect the system and make the system or server a hotspot of further cyberattacks. Systems without automated maintenance methods are usually running weak firmware capabilities, leaving such subjects to attacks that can make ideal botnet targets.
When the attacker deploys botnets in sufficient numbers of devices, s/he could command all the devices to send traffic at a large scale without the concern of the device owners. The network of the botnet-occupied devices is known as ‘zombie network’. Usually, the botnet malware remains silent until the command of the attacker.
However, the botnet can monitor the internet traffic of the host devices and spy on users' activity. As a result, it becomes a threat to personal information safe as it can be compromised.
Moreover, the attacker can get access to the other devices within the network of the botnet-affected devices. Only vulnerable devices become the target of the botnet and get infected. The most alarming feature of a botnet is that it can read, write system data and install applications from remote commands.
What are the Types of Botnet Attacks?
There are several types of botnet attacks that could affect the system. Each type of attack has its own characteristics and different features make them hard to detect.
Phishing itself is a widely spread cyberattack where the user is tricked by the attacker to share sensitive information that could make their devices vulnerable to phishing attacks. Furthermore, the affected devices could be used to initiate more phishing attacks within or without the network. However, botnet host devices could spread phishing links without notifying the device owner.
2. Brute Force Attacks
Brute force attacks are used to guess the password, secret key or any authentication details to gain access to computers, network systems, and web accounts. The old attack method is still effective at stealing passwords.
When a brute force attack originates from a botnet host device, it anonymously tries an excessive forceful attack to break the security code. Such attacks are common and flagged as highly risky issues to fix.
3. Distributed Denial-of-Service (DDoS)
Distributed Denial of Service is a cyberattack to disrupt the normal traffic of a network by sending a huge number of requests continuously. Such attacks are usually organized from computers, servers, or any network-connected devices. However, botnet-affected devices could be a part of any distributed denial of service (DDoS) attack. For example, a device that has been compromised with a botnet attack could attempt further DDoS attacks. As the attacker has control of the host device, s/he could easily use the device for even more planned cyberattacks.
What Are the Common Types of Botnets?
The concept botnet has a wide range of efficiency of cyberattacks in many forms. The above three are the basic types and the following are the common types of botnets.
1. DDos Attacks
From earlier discussion, DDoS attack is the flood of network traffic that causes denial of services. Moreover, the system could be completely destroyed because of heavy DDoS attacks.
Botnet hosts devices can communicate with other botnet devices or servers. As a result, any DDoS attack initiated from botnets may have multiple origins.
Heavy DDoS attacks are commonly used to stop any service unauthorizedly by confusing the host. Even nowadays botnets are being sold in many ‘black markets’.
Cyberattacks have become feasible (although unlawful) and outlay alternatives for anybody wishing to take down the server or disrupt connectivity between two or more networks. As a consequence, a variety of known cyberattacks emerge, varying from unscrupulous enterprises employing DDoS to obtain a strategic better position to attacks wherein DDoS is used as a weapon of destruction, retribution, or merely to put the server down.
2. Financial Breach
Another significant security threat of the botnet is its capability to steal financial information from your devices. Some botnets are designed to find and steal confidential financial information like credit card details, bank authentication information, and business information.
Additionally, botnets that are used to breach financial information spread within a network, the first attack the vulnerable device. After that, they transfer sensitive financial information, documents to the attacker.
3. Targeted Intrusions
As discussed earlier, a botnet can be used for many purposes. Accordingly, some botnets are programmed to attack specific vulnerable nodes and exploit the system to steal certain types of data.
Targeted intrusions of botnets are too dangerous for organizations and businesses because of their target-based attack. As a result, many companies become the target of such attacks and lose specific data including financial information, research and development data.
4. Email Spam
Email spamming is another common attack of botnets. Such attack can be organized primarily in two ways-
i. Your device can be affected by botnets from spam email
ii. Your device can be used to spread spam email.
In many cases, these two are used one by one to spread and attack more devices. First, when you click any malicious link from a spam email, the chances are high to get affected by botnets. Once you are affected by the botnet, your data can be sent to the attacker as well as your device could be used to spread botnets through email, network sharing, and many other ways.
What Are Botnets Used For?
Botnets can be used in many forms and for many purposes. Bots as well as botnets have a variety of distinct technical characteristics that make these well enough for lengthy incursions. A bot-herder may deploy bots to alter the whole organogram on what the attacker wants to perform. A botnet can also be used by other botnet-infected machines as access points, giving the bot-herder an almost endless number of ways to change to security configuration and settings.
Many cyberattacks, for instance, depend only on brute force, resulting in thousands of queries to a system or maybe even a device to enhance in addition to keeping it preoccupied to handle genuine traffic demands. If the botnet isn't particularly huge, someone else could take advantage of weakness inside a system's communication methods to increase the latency.
Here are the common uses of a botnet:-
1. Information theft
Botnets are frequently used to steal information as it was originated to do such theft from the affected devices. To steal the information an attacker may use spam or phishing email, and many other sources. It can be used by cybercriminals to deliver spam, spoofing, or even other schemes to users in order to defraud them of their funds and information.
The majority of botnet-enslaved system users are unaware knowing their devices have been compromised. The attacker wants the users of such systems trapped in such botnets to stay ignorant to the event that they are fraudsters' targets, so it may appear to be a little sluggish, malfunction periodically.
2. Cryptocurrency Scams
Botnets can be involved in cryptocurrency scams if the attacker plans such an attack tree. Invilvance of botnets is reported from many sources awarding the consequences. However, the number of cryptocurrency scams is less than the other attacks. Still the percentage of damage and fund compromisation is growing.
Attackers initially target social media sites like Facebook, youtube, and other platforms to spread the botnet among the users. In 2018, twitter faces a giveaway scam that spreads botnets. At that time Twitter blocked over 80 million accounts because of identified as spreading bot, malware, and spam.
As a new sensation, the cryptocurrency field is a lucrative target for the attacks to spread botnets and steal cryptocurrency funds.
3. Financial thief
Stealing financial information is one of the prime objectives of hackers that may cause financial damage to you and your organization. Most of the botnets attacks have a direct or indirect connection with financial theft and data compromisation. Moreover, each information is important in the financial territory. Credit card information, bank details, and even salary sheets of your organization can be compromised by botnet attacks.
Furthermore, the vast area of exploitation makes the botnet a strong way to gain access to financial data and documents. In many cases, the botnet used in financial theft is specially programmed to identify and send important financial documents automatically to the attacker.
4. Sabotage of Services
Botnets are largely involved in the sabotage of the service of many organizations. Depending on the attack vector and the scale of the attack, botnets could interrupt service for a maximum time.
Such attacks could have originated from any source of botnets. However, the form of attack and attack tree vary from target to target. In most of the attacks, botnets are used for the initial take over of a number of devices into the control of the attacker. After that, these devices are used to initiate further attacks to sabotage a service. Distributed Denial of Service (DDoS) attack is a common strategy to take a service down.
5. Selling access to other criminals
Botnets are now made as a product of trading in online black markets. The organogram is divided into two parts. One is the buyer of the botnets who doesn’t need to spread bots, simply s/he could buy bot networks. Another group of people is spreading bots and creating botnets to sell. These are sold in different scales including a number of devices, response time, and some other degrees.
Moreover, being affected by a botnet is a huge risk to your data security. Apart from the unauthorized use of your device to attack others, your sensitive information could be stolen. Most of the reported cases found the financial information as the most vulnerable for users and desired data of attackers.
Why are Botnets Created?
The introduction of Internet Relay Chat (IRC) in the late 1980s gave rise to the bot attack. Some earlier bots were developed at that time. A botnet designed to spread phishing links to the subscribers of Earthlink, a Broadband company that also provides email and website hosting, was among the first botnet attacks to gain public attention.
After 2000, botnets started growing in advanced dimensions. It started using in establishing peer-to-peer connections among users. Uses in p2p communication open the door of different attack scopes. In 2007, it was reported that the Zeus botnet hacks a large number of financial information and security credentials. After that another botnet named Gameover Zeus emerged in the scenario. That advanced version of the Zeus botnet worked using encrypted p2p connection and controlling the device or server. In a further aspect, it was able to run commands on the device to spread malware.
The increasing number of advertisements also increased the attack scope of botnets in past years. Till today, hackers continue to incorporate botnets to perpetrate ad fraudulently. Ad abuse occurs when individuals tap on and otherwise engage with adverts.
The development of internet of things (IoT) devices almost added 1.5 billion new devices to the internet and intranet communication. Much of these technologies are intrinsically unsecured, with default passwords or unpatched vulnerabilities, giving botnets an obvious target to penetrate.
How do Hackers Control their Botnets?
Botnets are created using the same means as other infections, such as phishing emails, fake web pages, and installations, media manipulation, or other standard infection mechanisms. The functioning of the fresh bot varies amongst various forms of the virus after first penetration.
Typically bots would use a variety of techniques to conceal themselves on the current internal network. Based upon that attack, the bot could be required to activate a backdoor, allowing expanded accessibility and hiding capabilities. A bot could also conceal itself by identifying its documents and programs similar to or identical to the system.
Botnets frequently pass the message to both systems through a centralized command structure. Such configuration is widespread since it is easy to set up and operate, yet instructions could be issued via proper procedures like IRC or HTTP. The above ensures message execution while also reducing connection complications. Creating a separate or a few centralized command centers, on the other hand, causes problems for hackers.
More modern malware may employ a number of clever tactics to conceal its operations and communications, making it difficult to locate bots and Command and Control Servers. Like the Mirai botnet, some may mask their running program identifiers to evade suspicion by host systems, or they could work in tandem with backdoors to gain more access privileges. Peer-to-peer traffic might create challenges to chase down a botnet, but the hosts remain consistent. Complex cyberattacks with botnets may employ techniques including such domain or IP fluxing. Because the CC server's Internet protocol or the web address is constantly changing, blocking and monitoring the services is nearly impossible.
With the exception of occasional checks for commands from the control device, your device will stay dormant. Meanwhile, the person in charge of the attack will concentrate on enlisting new machines to join the first botnet. The network might comprise thousands upon thousands of machines without facing consequences because they don't seem to be doing anything. Its administrators will almost certainly sell it or rent services on it, similar to outsourcing work. Hackers will transmit a message through the CC server at some point, causing the botnet to come out and start an attempt.
How is an Existing Botnet Disabled?
No universally accepted definition is found of what constitutes a botnet. Each botnet is distinct in terms of how it's established, how it spreads, or why it functions, making it difficult to identify. Most botnets are managed by a central server, while others are run on a peer-to-peer basis. Several bots use a form of pop-up advertisement to attack machines, while others use a clicked anonymous email. A few botnets can be used for mining bitcoin, while the rest are used to launch large-scale DDoS assaults.
A botnet may be hazardous in multiple ways: it can contaminate one or more of your machines, or it might utilize its joint efforts to launch DDoS or even other cyberattacks on your organization. To guard against the first, make absolutely sure that equipment is regularly patched and you have a competent botnet detection module.
It's also critical to safeguard your computers with anti-bot protection software that safeguards both your computers and the network toward which they're linked.
Disabling botnet includes the following two:
i. Detection: Botnets are often hard to detect but there are security tools to detect botnets. Nowadays with technical advancement, such security tools can detect botnets easily and efficiently.
For manual detection, you can keep a close look at your networking monitor and find any suspicious network routing to unknown sources.
ii. Block Instantly: Once you detect any suspicious activity or face a bot attack. Immediately try to neutralize them by blocking the network routing.
Keep eyes on the work process and block any unwanted service run by the machine.
Is a Botnet Illegal?
It depends on what basis the botnet is programmed and used on. Considering a large number of cyberattacks, botnets have positive uses too. Although the term is highly used in cybercrime the legitimate use of botnets exists. The model of distributed computing is largely similar to the work of botnets.
If the botnet is used for criminal activity, the consequences are definitely illegal. However, many large and powerful distributed systems are legal to use for a better computing experience.
How to Protect From Botnet Attacks?
Don't engage in any malicious sources you're not positive about or don't understand where they will go, although if they came from colleagues, relatives, or social networking contacts. Because their credentials might've been hacked.
You'll need strong virus protection software from a respected supplier installed. Avoid internet advertising that claims your machine has been infected; they are spyware disguised as ads.
Confirm that your security measures are enabled and upgraded if you use them. Use the anti-malware software to do a comprehensive scan. Your malware protection may be deactivated by a bot program.
For better security, you can use Two Factor Authentication (2FA) or Multi-Factor Authentication (MFA) in your security protocol to prevent unauthorized access from other networks.