6.1 Types of Malware and Their Behavior
2 min read•august 9, 2024
Malware comes in many forms, each with its own sneaky tactics. From viruses that hitch a ride on legit files to that holds your data hostage, these digital nasties can wreak havoc on systems and networks.
Advanced malware goes even further, using stealthy techniques to avoid detection. Rootkits hide in plain sight, while operates solely in memory. These crafty programs steal data, build botnets, and find new ways to spread and persist.
Types of Malware
Common Malware Categories
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- attaches to legitimate files or programs, spreads by infecting other files when executed
- self-replicates and spreads across networks without user interaction
- disguises itself as legitimate software to trick users into installing it
- Ransomware encrypts victim's files and demands payment for decryption key
- covertly gathers information about user activities and transmits it to a third party
- displays unwanted advertisements and collects user data for targeted marketing
Virus and Worm Characteristics
- Virus requires host program to spread, can infect executable files, boot sectors, or scripts
- Virus types include file infectors, boot sector viruses, macro viruses, and polymorphic viruses
- Worms exploit network vulnerabilities to propagate, can consume significant bandwidth
- Notable worm outbreaks include (2000), (2003), and (2017)
Malware for Financial Gain
- Ransomware variants include (encrypts files) and (locks device access)
- Ransomware attacks often target organizations with critical data (hospitals, government agencies)
- Spyware subcategories encompass keyloggers, screen scrapers, and password stealers
- Adware may bundle with free software, track browsing habits, and display pop-up ads
Advanced Malware Techniques
Stealthy Malware Tactics
- conceals malicious processes and files from detection by operating at a low system level
- Rootkit types include user-mode, kernel-mode, and firmware rootkits
- Fileless malware operates entirely in memory without writing files to disk, evading traditional antivirus
- Fileless attacks utilize legitimate system tools (PowerShell, Windows Management Instrumentation)
Data Theft and Network Control
- records keystrokes to capture sensitive information (passwords, credit card numbers)
- Keyloggers can be hardware-based (USB devices) or software-based (installed programs)
- consists of numerous infected devices controlled by a central command and control server
- Botnets can be used for (DDoS) attacks, spam distribution, or cryptocurrency mining
Malware Delivery and Persistence
- Advanced malware often uses social engineering techniques for initial infection ( emails)
- Malware may employ multiple stages to evade detection and establish persistence
- Some malware variants combine multiple techniques (rootkit capabilities with ransomware functionality)
- Zero-day exploits target previously unknown vulnerabilities, making them particularly dangerous
Key Terms to Review (33)
Adware: Adware is a type of software designed to display advertisements on a user's device, often in the form of pop-ups or banners. While it may not be as harmful as other types of malware, adware can slow down system performance and compromise user privacy by tracking browsing habits. It often comes bundled with free software, making it a common nuisance in the digital landscape.
Antivirus software: Antivirus software is a program designed to detect, prevent, and remove malicious software, commonly known as malware, from computer systems. This software plays a critical role in securing operating systems by providing real-time protection against various threats, including viruses, worms, trojans, and other forms of malicious code. In addition to scanning files and applications for known malware signatures, it can also monitor system behavior to identify suspicious activities that may indicate the presence of new or unknown threats.
Botnet: A botnet is a collection of compromised computers, known as 'bots' or 'zombies,' that are remotely controlled by an attacker to perform malicious activities, often without the owners' knowledge. These networks can be used to conduct various types of cyber attacks, such as Distributed Denial of Service (DDoS) attacks, where numerous bots overwhelm a target system with traffic, making it unavailable to users. Botnets exploit vulnerabilities in software or rely on social engineering techniques to spread and recruit new devices.
Crypto-ransomware: Crypto-ransomware is a type of malicious software that encrypts a victim's files, making them inaccessible until a ransom is paid to the attacker. This form of ransomware often targets individual users and organizations, exploiting vulnerabilities to lock data and demand payment, typically in cryptocurrency, to regain access. The rapid growth of crypto-ransomware reflects a troubling trend in the landscape of cyber threats, demonstrating the increasing sophistication of malware and the need for robust cybersecurity measures.
Data breach: A data breach occurs when sensitive, protected, or confidential data is accessed, disclosed, or acquired by unauthorized individuals. This can compromise the confidentiality of personal information, disrupt the integrity of data, and affect the availability of systems and services. Data breaches can result from various factors, including cyberattacks, human error, or inadequate security measures, impacting organizations and individuals alike.
Data Exfiltration: Data exfiltration is the unauthorized transfer of sensitive data from a computer or network, often with malicious intent. This process can involve a variety of methods, including hacking, phishing, or the use of malware to bypass security measures. It poses significant risks to organizations as it can lead to data breaches, loss of intellectual property, and compromise of personal information.
Defense in depth: Defense in depth is a security strategy that employs multiple layers of defense to protect information and information systems. By utilizing various security measures, such as firewalls, intrusion detection systems, and user training, this approach aims to reduce the risk of a successful attack and mitigate potential breaches. The idea is that if one layer fails, additional layers remain to provide protection against threats.
Distributed denial-of-service: A distributed denial-of-service (DDoS) attack is a malicious attempt to disrupt the normal functioning of a targeted server, service, or network by overwhelming it with a flood of internet traffic from multiple sources. This type of attack leverages numerous compromised computers or devices, often part of a botnet, to generate traffic that makes the target unavailable to legitimate users. DDoS attacks are significant in the realm of cybersecurity as they can cause extensive downtime and financial loss.
Dynamic analysis: Dynamic analysis is a technique used to examine the behavior of software or systems while they are in operation. This method helps in identifying vulnerabilities, malicious behavior, and performance issues by monitoring the program as it runs, enabling a comprehensive understanding of its interactions and effects on the environment. By focusing on real-time execution, this approach provides insights that static analysis may overlook, making it particularly useful for understanding malware and improving secure coding practices.
Fileless malware: Fileless malware is a type of malicious software that operates without being stored in a traditional file on a computer system, instead using legitimate system tools and processes to execute its attacks. This approach allows it to evade detection by conventional antivirus solutions, as it resides primarily in the memory rather than on disk. Fileless malware can exploit vulnerabilities in software or leverage scripting languages like PowerShell to carry out harmful actions while leaving little to no trace.
Firewall: A firewall is a security device or software that monitors and controls incoming and outgoing network traffic based on predetermined security rules. It serves as a barrier between a trusted internal network and untrusted external networks, helping to protect sensitive data from unauthorized access, cyber threats, and malware. Firewalls can be implemented in both hardware and software forms, and they play a critical role in the overall security architecture of a system.
Iloveyou: The 'iloveyou' virus was a computer worm that spread rapidly through email in May 2000, disguising itself as a love letter. It exploited social engineering by encouraging users to open the attachment, leading to widespread damage by overwriting files and sending copies of itself to the user's contacts. This incident highlighted vulnerabilities in both human behavior and software security, illustrating the impact of malware on information systems.
Intrusion Detection System: An Intrusion Detection System (IDS) is a security tool that monitors network traffic and system activities for malicious activities or policy violations. It plays a crucial role in identifying and responding to potential threats in real-time, thereby enhancing the overall security posture of organizations. By analyzing patterns and behaviors, IDS can detect unauthorized access, anomalies, and attacks, making it essential in today's digital landscape, especially with the increasing use of cloud computing and IoT devices.
Keylogger: A keylogger is a type of surveillance software or hardware that records every keystroke made on a computer or mobile device, often without the user's knowledge. This malicious tool is commonly used by cybercriminals to capture sensitive information like passwords, credit card numbers, and personal messages, making it a serious threat in the realm of cybersecurity.
Least privilege: Least privilege is a security principle that restricts users' access rights to the minimum necessary to perform their job functions. This concept aims to reduce the risk of unauthorized access or misuse of resources by limiting permissions and ensuring users can only interact with data and systems essential for their tasks.
Locker ransomware: Locker ransomware is a type of malicious software that restricts access to a victim's files or system until a ransom is paid. Unlike other ransomware that encrypts files, locker ransomware typically locks the entire screen or system, preventing the user from accessing their desktop or applications. This form of malware often displays a ransom note demanding payment in exchange for regaining access, causing significant disruption to the victim's daily activities.
Malvertising: Malvertising is a form of cyberattack that involves the use of online advertising to spread malware to unsuspecting users. This technique exploits legitimate ad networks and websites, allowing malicious code to be embedded in ads or redirect users to harmful sites without their knowledge. Malvertising is particularly dangerous because it can target a wide audience and can be difficult for users to recognize as malicious.
Password stealer: A password stealer is a type of malware designed to capture and transmit user credentials, such as usernames and passwords, from infected devices. These malicious programs can operate stealthily, often running in the background to avoid detection while collecting sensitive information that can be used for unauthorized access to accounts or systems.
Payload delivery: Payload delivery refers to the method by which malware transmits its malicious payload to a target system or network. This is a critical aspect of malware behavior, as it determines how effectively the malware can exploit vulnerabilities, spread, or execute its intended harmful actions after reaching the target environment.
Phishing: Phishing is a type of cyber attack where attackers impersonate legitimate entities to trick individuals into revealing sensitive information, such as passwords, credit card numbers, or personal details. This malicious practice often relies on social engineering techniques to create a sense of urgency or trust, making it easier for attackers to deceive their targets. Phishing can manifest in various forms, including emails, text messages, and even phone calls, linking it closely to broader concepts like social engineering, user authentication, and the behavior of malware.
Ransomware: Ransomware is a type of malicious software that encrypts files on a victim's computer, making them inaccessible until a ransom is paid to the attacker. This form of cyber threat has gained notoriety for its ability to cripple individual users and large organizations alike, often causing significant financial and operational harm. Ransomware attacks typically exploit vulnerabilities in systems or use social engineering tactics to trick users into installing the malware.
Rootkit: A rootkit is a type of malicious software that allows unauthorized users to gain control of a computer system without being detected. It often hides its presence and the actions of the attacker, making it extremely difficult to remove or identify. Rootkits can modify the operating system, providing the attacker with administrative-level access and enabling them to install additional malware or steal sensitive information without the user's knowledge.
Screen scraper: A screen scraper is a type of software that extracts data from the display output of other applications, typically from websites or desktop applications. It can automate the process of gathering information by simulating human interaction with the user interface, which can lead to unauthorized data access and potential misuse. In the context of malware, screen scrapers can be designed to harvest sensitive information, making them a tool for cybercriminals looking to exploit vulnerabilities.
Self-replication: Self-replication refers to the ability of malware to create copies of itself, often without user intervention. This feature allows malicious software to spread rapidly across systems and networks, making it a significant concern in the realm of cybersecurity. By harnessing various methods, such as exploiting vulnerabilities or leveraging social engineering, self-replicating malware can cause extensive damage and disruption.
Spyware: Spyware is a type of malicious software designed to secretly gather user information and send it to a third party without the user's consent. This software can track browsing habits, capture keystrokes, and collect sensitive data like passwords and credit card information. Spyware poses a significant risk to user privacy and can compromise both personal and organizational security.
SQL Slammer: SQL Slammer was a fast-moving computer worm that exploited a vulnerability in Microsoft SQL Server 2000, spreading rapidly across the internet in January 2003. It was known for its ability to cause widespread denial-of-service (DoS) attacks, overwhelming servers and disrupting internet services, showcasing the potential damage of malware and the importance of timely software patching.
Static analysis: Static analysis is a method of examining and evaluating computer software without executing it, typically performed during the development phase. It involves reviewing source code to identify potential vulnerabilities, bugs, or deviations from coding standards, ensuring that the software behaves as expected. This technique is crucial for maintaining software security and quality, especially in the context of malware analysis and secure coding practices.
System compromise: A system compromise occurs when an unauthorized user gains access to a computer system, allowing them to manipulate or steal data, disrupt services, or carry out malicious activities. This breach can happen through various vectors, including malware, social engineering, or exploiting vulnerabilities. Understanding the types of malware and their behaviors is crucial, as they often play a significant role in facilitating these compromises.
Trojan Horse: A Trojan Horse is a type of malicious software that disguises itself as a legitimate application or file to deceive users into downloading or executing it. Once activated, it can perform various harmful actions, including stealing data, installing other malware, or providing unauthorized access to attackers. Its name comes from the ancient Greek story where Greek soldiers hid inside a wooden horse to infiltrate the city of Troy, symbolizing how this malware tricks users into letting it in.
Virus: A virus is a type of malicious software that attaches itself to legitimate programs or files, enabling it to replicate and spread throughout a computer system. Once executed, a virus can cause various harmful effects, such as corrupting data, slowing down system performance, or even deleting important files. Viruses often rely on user interaction to spread, making them distinct from other types of malware that may operate without user consent.
WannaCry: WannaCry is a ransomware attack that emerged in May 2017, which exploited a vulnerability in Microsoft Windows to encrypt users' files and demand ransom payments in Bitcoin. The attack rapidly spread across the globe, affecting hundreds of thousands of computers in various sectors, including healthcare and government, highlighting the dangers of unpatched software and inadequate cybersecurity measures.
Worm: A worm is a type of malware that replicates itself in order to spread to other computers, often without any user intervention. Unlike viruses, which attach themselves to files or programs, worms are standalone software that exploit vulnerabilities in operating systems or applications to propagate across networks, making them particularly dangerous and efficient at spreading quickly.
Zero-Day Exploit: A zero-day exploit is a cyber attack that occurs on the same day a vulnerability is discovered and before a patch or fix is released. This type of exploit takes advantage of unaddressed security flaws in software or hardware, making it particularly dangerous because it can be used by attackers to compromise systems without any prior warning. Because the software vendor has not yet had the opportunity to develop and distribute a patch, zero-day exploits can lead to severe consequences for organizations and individuals alike.