Computers Basic MCQs Set-28

The thing that eventually terminates a worm virus is a lack of vulnerable systems to infect.

Worm viruses are self-replicating malware that can spread autonomously across computer networks and systems. They exploit security vulnerabilities in target systems to infect and propagate themselves to other vulnerable machines. However, once all vulnerable systems have been infected or patched to fix the vulnerability, the spread of the worm virus eventually halts.

A lack of vulnerable systems can terminate a worm virus because it relies on finding and infecting susceptible targets to continue its propagation. Once all vulnerable systems are patched or protected, the worm virus cannot find new hosts to infect, causing it to stop spreading.

To prevent the spread of worm viruses and protect systems, it is crucial to maintain up-to-date security practices. This includes regularly applying software updates and patches, using robust antivirus and anti-malware software, implementing network security measures, and practicing safe computing habits. By keeping systems secure and protected, the likelihood of a worm virus finding vulnerable targets is significantly reduced.

When a logic bomb is activated by a time-related event, it is known as a "time bomb."

A logic bomb that was created to erupt on Michelangelo's birthday is an example of a "time bomb" or "time-based logic bomb."

A logic bomb is a type of malicious code or program that remains dormant within a system until triggered by a specific event or condition. Once triggered, it executes a malicious action, such as deleting files, disrupting system operations, or causing other forms of damage.

In the case of a time bomb, the triggering event is based on a specific date or time. In the given example, the logic bomb is programmed to activate and cause damage on Michelangelo's birthday. This serves as a specific date-based trigger for the logic bomb to execute its malicious actions.

The Michelangelo logic bomb, also known as "Michelangelo virus," was a well-known example of a time-based logic bomb. It was designed to activate on March 6th, which is the birthday of the renowned Italian artist Michelangelo. When triggered, it had the potential to overwrite critical data on infected computers.

Time bombs can be particularly dangerous as they often remain undetected until the specific date or time arrives. This makes them challenging to identify and mitigate proactively. Proper security measures, such as up-to-date antivirus software, regular system scans, and adherence to safe computing practices, are essential in preventing and detecting the activation of time bombs or other forms of malicious logic.

The name of an application program that gathers user information and sends it to someone through the Internet is commonly referred to as a "spyware" or "keylogger" or "spyware".

Spyware is a type of malicious software that is designed to gather information about a user's activities without their knowledge or consent. It can monitor and record various actions, such as keystrokes, web browsing habits, passwords, and sensitive data. The collected information is then transmitted to a remote attacker or entity over the Internet.

Keyloggers, specifically, are a type of spyware that focus on capturing and recording keystrokes entered by the user. This allows the attacker to obtain usernames, passwords, credit card details, and other confidential information.

Both spyware and keyloggers are considered forms of malware and are typically installed on a user's system without their knowledge or consent. They can infiltrate computers through various means, such as malicious downloads, infected websites, or deceptive email attachments.

The purpose of such programs is often malicious, with attackers aiming to collect personal and sensitive information for identity theft, financial fraud, or other nefarious activities. Protecting against spyware and keyloggers involves using reputable antivirus and anti-malware software, regularly updating software and operating systems, being cautious when downloading files or clicking on links, and practicing safe browsing habits.

It's important to note that the use of spyware and keyloggers is illegal and unethical unless being used for legitimate purposes, such as law enforcement investigations with proper authorization.

Biometrics is the measurement of things such as fingerprints and retinal scans used for security access.

Biometrics refers to the use of unique physiological or behavioral characteristics of individuals to verify their identity. It involves the measurement and analysis of distinct features such as fingerprints, hand geometry, facial characteristics, iris patterns, voiceprints, or retinal scans.

These biometric measurements are captured using specialized devices or sensors, such as fingerprint scanners, iris scanners, or facial recognition cameras. The captured biometric data is then compared against a database of pre-registered biometric templates to authenticate or verify the identity of an individual.

Biometric systems offer several advantages over traditional security methods such as passwords or access cards. The unique nature of biometric characteristics makes it extremely difficult for an unauthorized person to forge or replicate them. Additionally, biometrics can provide a convenient and fast way for individuals to access secure areas or authenticate their identity.

Some common applications of biometrics include:

1. Access Control: Biometric systems are used to control access to secure areas, buildings, or computer networks. Individuals can gain entry by providing their biometric measurements instead of using keys, access cards, or passwords.

2. Time and Attendance Tracking: Biometric systems are used to record and track employee attendance, ensuring accurate tracking of working hours and preventing time fraud.

3. Identity Verification: Biometric systems can be employed for identity verification in various contexts, such as border control, financial transactions, or online account authentication.

4. Law Enforcement: Biometric technologies are used in law enforcement to identify individuals through fingerprint matching, facial recognition, or other biometric modalities.

5. Personal Devices: Biometric features, such as fingerprint or facial recognition, are commonly used in smartphones, tablets, or laptops for secure device unlocking and user authentication.

While biometric systems offer enhanced security and convenience, it is important to ensure proper protection and privacy of the biometric data. Strict security measures should be in place to safeguard the storage and transmission of biometric information and comply with privacy regulations.

Overall, biometrics provides a reliable and efficient means of verifying an individual's identity based on unique physical or behavioral characteristics, offering enhanced security and access control in various applications.

The most common tool used to restrict access to a computer system is a "password."

A password is a form of authentication that requires users to provide a unique combination of characters to verify their identity and gain access to a computer system, an application, a network, or specific resources. It serves as a barrier to prevent unauthorized individuals from accessing sensitive information or performing actions on the system.

Passwords are typically created by users and should be kept secret and known only to the authorized individual. They can be a combination of letters, numbers, and special characters, and their strength can be enhanced by using a mix of uppercase and lowercase letters, as well as avoiding easily guessable information.

When a user attempts to access a computer system, they are prompted to enter their username or user ID along with the corresponding password. If the entered password matches the stored password associated with that user account, access is granted. If the password is incorrect, access is denied.

Passwords are an essential aspect of computer security and access control. They provide a relatively simple and widely adopted method of restricting access to a computer system. However, it's important to note that the strength and effectiveness of passwords depend on various factors, such as their complexity, uniqueness, and how securely they are stored. It is advisable to follow best practices for password management, including using strong passwords, regularly updating them, and avoiding password reuse across multiple accounts.

In addition to passwords, other access control mechanisms such as biometric authentication (fingerprint, face recognition), two-factor authentication (2FA), and access control lists (ACLs) are also used to restrict access to computer systems, depending on the level of security required and the specific context of the system being protected.

Hardware or software designed to guard against unauthorized access to a computer network is known as a "firewall."

A firewall acts as a protective barrier between an internal computer network and external networks, such as the Internet. Its primary purpose is to monitor and control incoming and outgoing network traffic based on predetermined security rules. By doing so, it helps prevent unauthorized access, malicious attacks, and the spread of malware.

Firewalls can be implemented as both hardware devices and software applications:

1. Hardware Firewall: A hardware firewall is a dedicated physical device that is installed between a network and its connection to the Internet. It often comes in the form of a network appliance and operates at the network level, inspecting network packets and enforcing security policies. Hardware firewalls are typically deployed in corporate networks or larger network environments.

2. Software Firewall: A software firewall is a program or application that runs on a computer or network device to provide firewall functionality. It can be installed on individual computers or network devices to monitor and filter network traffic. Software firewalls are commonly used in personal computers, laptops, and small network setups.

Firewalls work by analyzing network traffic based on predefined rules or policies. They can be configured to allow or block specific types of network connections, ports, protocols, or IP addresses. Some common firewall features include packet filtering, stateful inspection, application-level filtering, and virtual private network (VPN) support.

Firewalls help protect computer networks by:

- Preventing unauthorized access: Firewalls monitor incoming and outgoing network traffic, blocking connections from suspicious or unauthorized sources.

- Filtering network traffic: They can be configured to filter traffic based on specific criteria, such as IP addresses, ports, protocols, or application types.

- Detecting and blocking malicious activity: Firewalls can identify and block known attack patterns, malicious content, or suspicious behavior, providing an additional layer of defense against cyber threats.

- Enforcing network security policies: They allow network administrators to define and enforce security policies, ensuring compliance and preventing unauthorized access to sensitive resources.

In summary, firewalls are essential security components that protect computer networks by monitoring and controlling network traffic, preventing unauthorized access, and defending against malicious attacks. They are a fundamental part of network security infrastructure, providing an important layer of defense for both personal and enterprise networks.

The scrambling of code is known as "obfuscation."

Obfuscation is a technique used to deliberately make code or software more difficult to understand or reverse-engineer. It involves transforming the code in a way that maintains its functionality but makes it challenging for humans to comprehend.

The primary goal of code obfuscation is to make it more difficult for unauthorized individuals to analyze and understand the code, protecting it from reverse engineering, tampering, or unauthorized modifications. It is often employed in commercial software, proprietary algorithms, or applications where code confidentiality and intellectual property protection are paramount.

Obfuscation techniques can include:

1. Code Encryption: The code is encrypted using various algorithms or keys to prevent direct analysis.

2. Variable and Function Renaming: Meaningful names of variables, functions, or classes are replaced with arbitrary or meaningless names, making it harder to understand the code's logic.

3. Control Flow Obfuscation: The structure of the code is modified to confuse the flow of execution, using techniques like adding unnecessary branches, inserting junk code, or altering loops.

4. Code Compression: The code is compressed or packed to reduce its size and make it more challenging to analyze.

5. String Encryption: String literals in the code, such as error messages or hardcoded values, are encrypted to hide their content.

By obfuscating the code, it becomes more challenging for someone to decipher its internal workings, algorithms, or security mechanisms. However, it's important to note that code obfuscation does not provide complete security or protection against determined attackers. Skilled reverse engineers can still employ various techniques to deobfuscate and understand the code.

Code obfuscation is commonly used in commercial software protection, licensing enforcement, and preventing software piracy. It helps make the code more resistant to reverse engineering attempts, discouraging unauthorized use or modification.

To prevent the loss of data during power failures, use an "uninterruptible power supply" (UPS).

An uninterruptible power supply, commonly known as a UPS, is a device that provides temporary backup power to connected devices or systems in the event of a power outage or fluctuation. It acts as a power protection solution by offering a reliable and uninterrupted power source to critical equipment, such as computers, servers, networking devices, and data storage systems.

A UPS typically consists of a battery or batteries that store electrical energy. When the main power supply experiences an interruption or voltage fluctuations, the UPS seamlessly switches to battery power, ensuring a continuous and stable supply of electricity to connected devices. This allows them to continue operating without disruption, giving users sufficient time to save their work, perform graceful shutdowns, or switch to alternative power sources.

UPS devices come in various sizes and capacities, depending on the power requirements of the connected equipment and the desired backup duration. Small UPS units are commonly used for personal computers or home office setups, while larger UPS systems are deployed in data centers, server rooms, and enterprise environments.

In addition to providing backup power, UPS units often offer other features for power conditioning, surge protection, and voltage regulation. They help mitigate the risks of data loss, hardware damage, and system instability that can occur during power outages or electrical disturbances.

When selecting a UPS, factors such as the power capacity, battery runtime, number of outlets, and compatibility with the devices being protected should be considered. It's also important to regularly maintain and test the UPS to ensure it remains in good working condition and can effectively protect against power-related data loss or disruptions.

Overall, a UPS is an essential component of a comprehensive data protection strategy, safeguarding against the potential loss or corruption of data caused by power failures, voltage fluctuations, or other power-related issues.

Cybercrime is defined as any crime completed through the use of computer technology.

Cybercrime encompasses a wide range of illegal activities that are facilitated or carried out using computers, networks, and the Internet. It involves the use of technology as a tool or target for criminal activities, often with the aim of gaining unauthorized access, causing harm, or obtaining financial gain.

Examples of cybercrime include:

1. Hacking: Unauthorized access to computer systems or networks to gain information, disrupt operations, or steal data.

2. Malware Attacks: Spreading malicious software, such as viruses, worms, ransomware, or spyware, to compromise systems or steal sensitive information.

3. Phishing and Social Engineering: Deceptive techniques used to trick individuals into revealing sensitive information, such as passwords or financial details, through fraudulent emails, websites, or phone calls.

4. Identity Theft: Illegally obtaining and using someone else's personal information, such as Social Security numbers or credit card details, for fraudulent purposes.

5. Online Fraud: Engaging in fraudulent activities, such as online scams, fake auctions, or pyramid schemes, to deceive victims and extract money or valuable assets.

6. Cyberstalking and Harassment: Using technology to intimidate, threaten, or harass individuals online.

7. Data Breaches: Unauthorized access or exposure of sensitive data, often resulting in the compromise of personal information or trade secrets.

8. Cyber Espionage: Illegally accessing and stealing confidential information from government agencies, organizations, or individuals for political, economic, or military gain.

9. Distributed Denial of Service (DDoS) Attacks: Overwhelming a target's network or website with a flood of traffic to disrupt its normal functioning and deny access to legitimate users.

10. Online Child Exploitation: Producing, distributing, or accessing child pornography or engaging in grooming activities.

These are just a few examples of the diverse range of criminal activities that fall under the umbrella of cybercrime. Due to the widespread use of computers and the Internet in modern society, cybercrime poses significant challenges to individuals, organizations, and law enforcement agencies worldwide. Efforts to combat cybercrime involve technological advancements, cybersecurity measures, international cooperation, and the enactment of appropriate laws and regulations.