In today's digital world, botnet attacks have become an increasing threat. Botnets are complex networks that allow hackers to infiltrate target systems and take control of millions of devices. These botnets often operate without users being aware, offering attackers a powerful weapon. Botnet attacks allow cybercriminals to carry out their malicious intentions such as theft, phishing, ransomware attacks, and even cyber warfare activities against a variety of targets. These attacks can affect both individual users and corporate networks, causing significant data loss, financial harm and reputational damage. In this article, we will examine in detail how botnet attacks work, their common areas of use and their potential effects, and discuss the measures that can be taken to combat this threat.
How do botnet networks work?
Botnet networks have a complex structure consisting of infected devices, usually controlled by a group of malicious individuals or organizations. These networks are often infected with viruses, Trojan horse or by infecting targeted devices through malware. The targets of botnets are various devices such as computers, smartphones, tablets, IoT devices, and even servers.
To create a botnet network, attackers, in the first step, distribute malicious software to infect target devices. This malware often comes from rogue files that users unknowingly download or exploit vulnerabilities. Once the malware infects the target device, it creates a “system” that provides feedback to the attackers and receives their commands.bootsIt starts operating as ".
The main control point of the botnet network is the attackers'command and control” (C&C) server is a central server he calls. This server is a central control point through which attackers will forward commands and instructions to all bots. Through these commands, attackers can simultaneously control all infected devices connected to the botnet network and make them perform certain actions.
Botnet networks can implement different attack tactics using infected devices. For example, DDoS (Distributed Denial of Service) It can send large amounts of traffic to target systems with its attacks, consuming their resources and causing them to crash. Additionally, botnets, phishing attacks, data theft, ransomware attacks and may perform harmful activities such as sending spam.
Botnet Attack Types
1- DDoS Attacks (Distributed Denial of Service)
Botnets usually DDoS attacks using for. In this type of attack, infected devices under the control of the botnet ensure that large amounts of traffic are sent to the target system or network. The intensity of this traffic consumes the target's resources and prevents services from operating normally, thus rendering target systems unusable.
2- Phishing Attacks
Botnets are also used in phishing attacks targeting users. Botnet owners attempt to steal personal information or login IDs by tricking users through fraudulent emails or fake websites. This information can then be used for malicious purposes.
3- Data Theft
Botnets can infiltrate computers and networks and steal data. Through infected devices, attackers can capture users' personal information, financial data or sensitive company information. This information can then be used in malicious activities or sold on black markets.
4- Ransomware Attacks
botnets, ransom It is used in the distribution of software. Through infected devices, attackers infect target systems with malware and then encrypt files to prevent access. They may then demand ransom and demand payment to solve the files.
5- Sending Spam
Botnets can be used to send large amounts of spam emails. Infected devices create fake emails and send them to targets containing malicious content or unsolicited advertisements. This makes it easier to bypass spam filters and spread unwanted content.
How are botnet attacks carried out?
Botnet attacks are typically carried out through the following steps:
Infection phase in botnet attacks, attackers infect target devices with malware It is a critical step aimed at. This step involves the methods used by cyber attackers to hijack target devices and include them in the botnet network. Infection is usually accomplished by attackers skillful use of a variety of methods and tactics.
- Attackers use a variety of tools to launch the infection. For example, it tries to trick users through email attachments or malicious links. Malware hidden in email attachments or links infects the device by exploiting users' security vulnerabilities. In addition, exploit kits and attacks targeting security vulnerabilities are also frequently used in the infection process. Attackers attempt to infiltrate devices by detecting security vulnerabilities and infect target systems with malware.
- Infected target devices attempt to join the botnet network by communicating with the control server. The malware connects to servers controlled by the attackers, receives commands and acts according to the attacker's wishes. In this way, a botnet network consisting of thousands or even millions of devices is created.
- Infection stage, It is a complex process in which cyber attackers use advanced techniques and strategies. Attackers to deceive users social engineering tacticsuses automated tools and complex coding methods to detect vulnerabilities. Therefore, it is of great importance to take precautions such as increasing users' security awareness, using up-to-date software and fixing security vulnerabilities.
Creating the Bot Network
Infected devicesconnects to the botnet network to receive commands and instructions specified by the control server. At this stage, infected devices are “boots” and operates under the control of attackers. Bots regularly communicate with the control server and receive instructions from the attackers.
Command and Control
Bots are programmed to execute commands and instructions they receive from the control server. These instructions, DDoS attacks, phishing attacks, data theft or other harmful activities It may include various types of attacks, such as: Through the control server, attackers can send commands to all bots simultaneously and coordinate the botnet network.
Botnet owners use bots in the botnet network to reach designated targets. attack executes. For example, in DDoS attacks, bots send massive traffic to the target system or network, consuming its resources and preventing services from operating normally. In phishing attacks, bots try to trick users into stealing their personal information through fake websites or fraudulent emails.
Confidentiality and Continuity
Botnet attacks are often designed so that it is difficult to track attackers. Attackers can encrypt communication between infected devices or use different IP addresses. Additionally, new infected devices are constantly being discovered to ensure the continuity of botnets. Attackers use different methods and tools to bypass security measures and disguise botnets.
Botnet owners use administrative tools and control panels to manage the botnet network. These tools are used to monitor the status of infected devices, add new infected devices, send commands, and generally manage the activities of the botnet. Attackers constantly work to update bots in the botnet, develop new attack tactics, and improve the efficiency of the botnet.
Who is the target of botnet attacks?
Botnet attacks can be carried out against individuals and organizations in various sectors. Below are some potential individuals and organizations that could be the target of botnet attacks:
- Individual Users: Botnet attacks can target individual users. Attackers may engage in malicious activities such as stealing personal information, sending ransom demands, or conducting phishing attacks through infected devices.
- Companies and Organizations: Botnet attacks can target the cybersecurity of companies and organizations. Attackers can infiltrate company networks and steal data, capture company information, or block network services. It can also demand money from companies or damage their reputation through ransomware attacks.
- Public Institutions and Governments: Botnet attacks pose a significant threat to public institutions and governments. By infiltrating government networks, attackers can access sensitive information, disrupt government services, or cause information leaks. Such attacks can pose a threat to a country's critical infrastructure.
- Financial Institutions: Botnet attacks can target organizations in the financial sector, such as banks, payment processors and other financial institutions. Attackers can capture customer information or target financial resources by performing phishing attacks against these organizations.
- E-Commerce Sites: Botnet attacks may aim to gain financial gain by targeting e-commerce sites. Attackers can perform DDoS attacks against these sites, causing service interruptions or stealing users' information.
Important Botnet Attacks Known in the World
EarthLink Spammer – 2000
The first case in which botnets became widely known was the emergence of a spammer created by Khan K. Smith in 2000. This botnet made a huge impact, sending 1.25 million emails (phishing scams that mimic communications from legitimate websites) in just over a year. Smith hoped to collect sensitive information, such as credit card numbers or viruses that infect computers, and obtain information remotely. However, Smith, who is facing a $25 million lawsuit from EarthLink, was accused of using their network for a spam scheme. This case earned him at least $3 million.
Cutwail – 2007
2009 yılında, spam botnet Cutwail, dakikada 51 milyon e-posta göndererek dünya genelindeki spam hacminin %46,5’ine katkıda bulunuyordu. Cutwail, yaklaşık 1,5 milyon virüslü makineden oluştuğu için, onu kapatma çabaları son derece etkisiz kaldı. 2014 yılında FBI, Europol ve diğer kolluk kuvvetleri tarafından gerçekleştirilen bir müdahaleye rağmen, bugün bile botnet hala aktif durumda ve kiralanabilir bir hizmet olarak sunulmaktadır.
Grum – 2008
Grum, farmasötik spam konusunda uzmanlaşmış bir spam botnetti ve oldukça büyük bir ölçekte faaliyet gösteriyordu. 2009 yılında, Grum günde 39,9 milyar mesaj göndererek dünya genelindeki istenmeyen postaların %18’ini oluşturuyordu. Ancak, kolluk kuvvetleri Grum’un komuta ve kontrol merkezlerini keşfetmek için yoğun bir çalışma yürüttü. Bu operasyon, 2012 yılında başarıyla gerçekleştirildi ve merkezlerin Hollanda’dan Panama’ya kadar olan bölgelerde olduğu tespit edildi. Bu müdahale sayesinde Grum’un faaliyetleri durduruldu ve spam botnetin etkisi büyük ölçüde azaltıldı.
Kraken – 2008
Kraken botnet’in tam boyutu hakkında kesin bir bilgi olmasa da, geniş kapsamı göz ardı edilemez. Tahminlere göre, Kraken’in Fortune 500 şirketlerinin %10’unu etkilediği ve yaklaşık 495.000 botun her birinin günlük olarak 600.000’e kadar e-posta gönderebileceği düşünülüyor. Botnet, kötü amaçlı yazılımdan koruma yazılımı tarafından tespit edilmekten kaçınmak için kaçırma tekniklerini kullanmasıyla dikkat çekti. Kraken, güncellendiğinde bile otomatik olarak güncellenen ilk gözlemlenen botnetlerden biriydi. Kraken bugün aktif olmasa da, geçmişte güvenlik sistemleri tarafından tespit edilen kalıntıları vardır ve gelecekte yeniden ortaya çıkma potansiyeline sahiptir.
Methbot – 2016
Methbot fraudulently obtained hundreds of thousands of IP addresses from two global internet registries and linked them to US-based internet service providers. The operators of this botnet have created more than 6,000 domains and 250,267 different URLs that appear to be top-notch publishers. It had advertisers bid on those domains and then sent its bots to “watch” nearly 300 million video ads every day. Methbot was discovered and completely blocked by White Ops in 2015. However, we always observe signs of Methbot reemergence and therefore caution is required.
Mirai – 2016
The Mirai botnet blocked access to many internet services on the east coast of the United States in a massive distributed denial of service (DDoS) attack. But what made Mirai stand out was that it was the first major botnet to infect unsecured IoT (internet of things) devices. At its peak, the worm spread across more than 600,000 devices. The most surprising part of this is that the botnet was created by a group of university students who wanted to gain an advantage in the game Minecraft. Mirai leveraged the use of simple passwords or weak security measures to attack these IoT devices. This incident was a major turning point, highlighting the potential risks of vulnerable IoT devices and the broad scope of botnet attacks.
Known botnet attacks in Turkey and the World
MisoSMS, a dangerous botnet discovered by security company FireEye, scans and steals SMS messages from users in South Korea. Stolen SMS messages were later sent to China hackerIt is sent to the e-mail addresses of . This botnet takes action by installing an application that introduces itself as Google Vx.
The application asks users for administrator rights, and many users allow it because they are not aware of the danger. The application starts playing SMS messages after receiving the user's approval. The stolen SMS messages are then sent in bulk through a system controlled by more than 450 email accounts to share with hackers. According to FireEye, hackers regularly read stolen SMS messages.
The boat targeting President Erdoğan and the Libya Operation
A network of more than 9,000 bot accounts operating on Twitter and serving the political interests of the United Arab Emirates and Saudi Arabia has been identified and shut down. This bot network was publishing posts criticizing Turkey's intervention in Libya, targeting President Recep Tayyip Erdoğan. He was also sharing posts aimed at using the COVID-19 epidemic for political purposes.
The network was first reported to Twitter by the Stanford Internet Observatory in December 2019 and was later discovered by an Indiana-based researcher. Accounts shared with Digital Forensic Research Lab (DFRLab) and BuzzFeed were examined with analysis confirming that they were bot accounts. This bot network served functions such as supporting campaigns and providing greater reach to the masses through the use of hashtags for certain purposes.
DFRLab has documented artificial agenda-setting botnets ranging from the promotion of a Korean pop group to political campaigns in India, and produced a comprehensive report on coordinated operations on Twitter to promote Emirati interests in Libya and other regions.
How can you prevent your computer from becoming part of a Botnet?
- Stay Updated: Update your operating system, applications, and security software regularly. Updates are important to improve your computer's security and fix known vulnerabilities.
- Use Strong Passwords: Protect your accounts using strong and unique passwords. It is important that passwords are complex, unpredictable, and strengthened by multiple factors (e.g. two-factor authentication).
- Use Security Software: Security software is critical for detecting, blocking and eliminating malware. Detecting malicious software and preventing unauthorized access attempts is a fundamental requirement for ensuring network security.
Among security software, antivirus programs are used to detect and remove malicious software. These software constantly scan your computer and detect known malware. The firewall protects your network and creates a barrier against unwanted access. It increases the security of your network by blocking unauthorized network traffic.
Many network administrators prefer well-known and reliable brands such as Kaspersky, Symantec, McAfee for security software. These software have a large malware database and are constantly updated to protect against new threats.
It is also important to update security software regularly. As attackers are constantly developing new and sophisticated malware, updates are important to combat these new threats. Therefore, it is recommended to enable the automatic update feature of security software and check for updates regularly.
Network admins must effectively configure security software, optimize its settings, and enforce security policies when necessary. Additionally, network security can be further strengthened by using additional security measures such as network monitoring and intrusion detection systems, as well as security software.
- Beware of Phishing Attacks: Be wary of suspicious emails, links and downloads. Be careful not to click on content from unknown or unreliable sources.
- Use an Effective Spam Filter: Use an effective spam filter that blocks spam emails and unwanted messages. This way, you will not be exposed to messages containing malicious links or harmful attachments.
- Monitor Network Traffic: By regularly monitoring your network traffic, you can detect unexpected or suspicious activity. Abnormal data transfers or connections may be signs of a botnet attack.
- Update Your Network Devices: Regularly update the firmware of your modems, routers and other network devices. These devices may also contain security vulnerabilities, so it's important to stay on top of updates.
- Make Regular Backups: Back up your important data regularly. This way, you can protect and quickly restore your data in the event of a possible botnet attack or other security incident.
- Secure Your Internet of Things (IoT) Devices: To secure your IoT devices, such as smart home devices, change default passwords, monitor for updates, and take security measures when necessary.
- Beware of Unknown Email Attachments: Avoid opening unfamiliar or unexpected email attachments. They may contain malicious codes or malware.
- Download from Trusted Sources: Download your software from reliable sources. It is safer to download from sources such as official websites and trusted app stores.
- Use Two-Factor Authentication: Enable two-factor authentication on your accounts. This helps prevent unauthorized access by adding an additional layer of security to your accounts.
- Report Suspicious Activity: Report suspicious emails, fraudulent attempts, or malicious activity to the appropriate authorities. This is important to protect other users and ensure that relevant security measures are taken.
- Be Informed and Keep Yourself Updated:Being aware of security issues provides a significant advantage in combating cyber threats. Keeping up with developments in security and understanding current threats is the first step in protecting your computer and personal information.
First of all, it is necessary to be careful against social engineering attacks. Social engineering is an attack method where attackers use manipulative tactics to gain access to sensitive information by gaining people's trust. Attackers can use channels such as fake emails, voicemail messages, phone calls or social media to trick people and obtain their personal information. Therefore, you should avoid sharing data with people you do not know or sources you do not trust, and carefully evaluate suspicious communications.
You should be conscious about safe internet use. You should avoid accessing suspicious or untrusted websites, use secure and encrypted connections, and set strong passwords for your online accounts. Before opening email attachments or downloads, it's important to check them with scanning tools to make sure they're trustworthy.
Finally, you should use reliable sources to keep up to date with threats and security measures. Certified security experts, technology blogs, security forums, and publications from official security organizations are useful sources for accessing up-to-date information. By following these resources regularly, you can stay informed about cyber threats and keep yourself updated.
What damages can it cause to your business?
A botnet attack in your business can cause serious damage and consequences. Here are the damages botnet attacks can potentially cause to your business:
1. Service Interruption
Botnet attacks can overwhelm your network and servers under heavy demands, leading to service outages. The attack can consume network resources, denying access to legitimate users and rendering your website or online services unusable. This can lead to customer dissatisfaction, loss of revenue and damage to your reputation.
2. Data Theft
Botnets can be used to steal your sensitive data. Attackers can navigate your business's network using computers under the control of the botnet and capture important information such as usernames, passwords, customer information and financial data. This information can lead to phishing attacks or fraud and undermine your business reputation and customer trust.
3. Financial Losses
Botnet attacks can cause direct financial losses to your business. Factors such as service interruption, loss of customers, loss of reputation and measures required to ensure business continuity can lead to loss of revenue. Additionally, theft of your financial information as a result of data theft or encountering ransom demands may also cause financial losses.
4. Loss of Reputation
A botnet attack can negatively impact your business's reputation. Service outages, security breaches, or data breaches can undermine your trust with your customers.
5. Loss of Customer Trust
A botnet attack can undermine your customers' trust. Situations such as theft of sensitive information or service outages can cause customers to worry about the security of their personal and financial data. This can cause customers to lose trust in your business and look for another alternative.
6. Legal Issues
Botnet attacks can cause your business to face legal problems. For example, if attacks cause damage to other businesses or users, you may face legal battles and compensation claims. Additionally, in the event of data breaches or violations of personal data protection laws, you may face criminal investigations and fines.
7. Business Continuity Risk
A botnet attack can compromise your business continuity. Service interruptions or data loss can impact your business processes, disrupt your customer service, and reduce the productivity of your employees. Taking precautions to ensure business continuity and dealing with the post-attack recovery process can mean loss of time and resources for the business.
InfinitumIT Cyber Security Consultancy Service
InfinitumIT provides businesses with cyber security By providing expertise, consultancy and solutions, it helps them identify security vulnerabilities, reduce risks and protect against attacks.
InfinitumIT Cyber Security Consultancy service includes:
- Threat Assessment: An assessment is performed to determine how vulnerable your business is to cyber threats. This assessment may include examining network infrastructure, software and applications, security policies, and employee security awareness.
- Risk Analysis and Management: A risk analysis is performed to identify and manage the security risks your business faces. Potential risk areas such as the business's sensitive data, business processes, software and hardware are evaluated. A risk management plan is then created to prioritize risks and determine appropriate countermeasures.
- Security Infrastructure and Solution Design: Suggestions are offered to strengthen the security infrastructure of your business. This may include the installation of firewalls, intrusion detection systems, security software and other technological solutions. A customized security solution is designed to suit your business's needs and budget.
- Monitoring and Incident Response: Monitoring systems and automatic alarm mechanisms are installed to constantly monitor your business's network, systems and applications and detect potential attacks. Additionally, emergency response plans are created to quickly respond to cyber attacks and minimize their effects.
- Awareness Trainings: Training programs are organized to increase cyber security awareness for business employees. These trainings provide information about common threats such as social engineering attacks, malware, phishing, and encourage safe work habits.
- What is a botnet?A botnet is a network formed by bringing together many computers or devices under the control of malicious people or hackers. These computers are often called zombie computers and are controlled remotely without the knowledge or permission of their owners. Botnets are often used for malicious activities, such as DDoS attacks, spamming, phishing and malware distribution.
- What does a computer turned into a zombie mean?A zombified computer is a computer or device controlled by a malicious person or hacker. Such computers are often infected through malware or worms and can be controlled remotely without the owner's knowledge or permission. Zombie computers are used as part of botnets to carry out attacks or carry out malicious activities.
- What is a Botnet Network?A botnet network is a network of zombie computers or devices controlled by malicious individuals or hackers. This network is often used for purposes such as transmitting the botnet owner's orders, performing command and control, coordinating attacks, and gathering information. Botnet networks often have a distributed structure, making it difficult to detect and block the botnet.
- What is a DDoS attack and how does it relate to a botnet?A DDoS (Distributed Denial of Service) attack is a type of attack that directs a large amount of traffic to a targeted website, server or network, causing resources to be exhausted and the service to become unusable. Botnets are frequently used to carry out DDoS attacks. By using zombie computers connected to the botnet network, the botnet owner creates a large traffic flow and overloads the target system or network. This exhausts the target's resources and causes the service to become unavailable.
- What is DDoS?A DDoS (Distributed Denial of Service) attack is a type of attack that sends a large amount of traffic, requests or data to a targeted system, network or resource, causing resources to be overloaded and service interruption. DDoS attacks are often carried out using traffic from multiple sources, different geographic locations, and often malicious networks such as botnets. These attacks can lead to excessive resource consumption on the target system, exceeding network bandwidth limitations, or exhausting infrastructure resources.
- How do hackers control botnets and for what purposes?hackers, they often use malware or worms to control botnet networks. These malware are used to infect zombie computers and allow hackers to control computers remotely. Hackers can manage zombie computers connected to the botnet network through the control panel or command and control servers. In this way, it can coordinate attacks, carry out malicious activities, steal sensitive information or perform other harmful actions.
- What are the common methods used in botnet attacks and how do they work?Methods commonly used in botnet attacks include strategies such as using Command and Control (C&C) servers, phishing campaigns, exploit kits, and zombie computers. You can better understand botnet attacks by understanding the working principles of these methods, how attackers gain control, and how infected computers are used.
- Which sectors are generally the targets of botnet attacks and why are these sectors preferred?Targets of botnet attacks are generally sectors such as financial institutions, e-commerce platforms, large enterprises, government institutions and critical infrastructure providers. These sectors are attractive targets for attackers because they contain large amounts of data and resources. In addition, botnet attacks may be aimed at gaining financial gain, damaging reputation or cyber espionage.
- What methods and tools are used to detect and respond to botnet attacks?Methods and tools such as network monitoring, security incident management, and threat intelligence analysis are used to detect and respond to botnet attacks. In this process, technologies such as Intrusion Detection Systems (IDS), Intrusion Prevention Systems (IPS), Security Information and Event Management (SIEM) systems, network analysis tools, malware detection systems and firewalls are used. Additionally, it is important for cybersecurity professionals to constantly stay up to date and monitor new threats to monitor, analyze and respond to botnet attacks.