Computer Science MCQs – Page 81 (Q801-810)

Shoulder surfing, in the context of computer security, is correctly defined as secretly observing someone's screen, keystrokes, or password entry to steal information, a low-tech but surprisingly effective attack method where an observer simply watches over a victim's shoulder, whether in person at an ATM or office, or remotely using binoculars or hidden cameras, to capture sensitive information like PINs, passwords, or confidential documents. This technique doesn't require any technical hacking skill or software, relying instead entirely on physical proximity and a victim's lack of awareness of their surroundings while entering sensitive information in public or semi-public spaces. Simple countermeasures include covering the keypad when entering a PIN, being mindful of who might be able to see a screen in public settings like coffee shops or public transportation, and using privacy screen filters that limit screen visibility to narrow viewing angles. Understanding shoulder surfing as a genuine, low-tech security threat highlights that effective cybersecurity requires physical awareness alongside purely digital protective measures.

A common sign of a phishing email is correctly that it creates urgency, has suspicious links, or requests sensitive information, using psychological pressure tactics like threatening account suspension or claiming a limited-time offer to rush recipients into acting quickly without carefully scrutinizing the message's legitimacy. Other common phishing red flags include mismatched or slightly altered sender email addresses that closely mimic a legitimate organization, generic greetings instead of a recipient's actual name, poor spelling or grammar, and links that, upon hovering, reveal a URL that doesn't match the supposedly legitimate organization the email claims to represent. Recognizing these common warning signs is an essential practical cybersecurity skill, since phishing remains one of the most prevalent and effective attack methods precisely because it exploits human psychology and trust rather than relying purely on technical vulnerabilities. Understanding these red flags empowers individuals to critically evaluate suspicious emails before clicking links, downloading attachments, or providing any requested sensitive information.

The safest action when receiving a suspicious email with an unknown attachment is correctly to avoid opening it and verify the sender before taking any action, since malicious attachments remain one of the most common ways malware is initially delivered onto a victim's system, often disguised as legitimate documents like invoices, resumes, or official notices. Verification can involve directly contacting the purported sender through a separate, trusted communication channel, such as a known phone number, rather than replying directly to the suspicious email itself, since a compromised or spoofed account might respond convincingly while still being fraudulent. This cautious approach reflects the broader cybersecurity principle of maintaining healthy skepticism toward unexpected digital communications, particularly those creating urgency or requesting unusual actions, rather than assuming good faith by default. Understanding and practicing this verify-before-acting approach is a fundamental, practical cybersecurity habit relevant to avoiding a significant proportion of common malware infections and phishing scams.

Social engineering, in the context of cybersecurity, is correctly defined as manipulating people into divulging confidential information or performing actions that compromise security, exploiting human psychology, trust, and social norms rather than relying on purely technical vulnerabilities to gain unauthorized access to systems or sensitive data. Common social engineering tactics include phishing emails, pretexting (creating a fabricated scenario to justify requesting sensitive information), baiting (offering something enticing to lure a victim into a trap), and impersonating trusted figures like IT support staff or company executives. This human-focused attack approach is often considered one of the most effective and dangerous categories of cybersecurity threats, since even the most sophisticated technical security measures can be circumvented if an attacker successfully manipulates an authorized individual into voluntarily providing access or information. Understanding social engineering as a fundamentally psychological rather than purely technical attack vector underscores why ongoing security awareness training for employees remains such a critical component of comprehensive organizational cybersecurity strategy.

It is recommended not to reuse the same password across multiple accounts correctly because if one account is compromised, reused passwords put all other accounts at risk too, meaning that if an attacker obtains a password from a single data breach at one service, they can then attempt to use that same stolen password to access a victim's other accounts across completely different, unrelated websites and services. This attack technique, known as 'credential stuffing,' is particularly effective and widespread precisely because so many people reuse the same or similar passwords across numerous different accounts for convenience, allowing a single data breach to potentially compromise a victim's entire digital identity across many services. Using unique passwords for each account effectively contains the damage from any single data breach, ensuring that even if one account's password is stolen, an attacker cannot simply reuse it to access the victim's other accounts. Password managers are commonly recommended specifically to make maintaining unique, strong passwords across numerous accounts practically manageable without requiring users to memorize dozens of complex, distinct passwords.

A firewall is correctly designed to monitor and control incoming and outgoing network traffic based on security rules, acting as a protective barrier that examines data attempting to enter or leave a network or device, blocking anything matching predefined suspicious patterns or violating established security rules while allowing legitimate traffic to pass through normally. Firewalls can be implemented as dedicated hardware devices protecting an entire network's perimeter, or as software running on an individual computer, with most modern operating systems including a built-in software firewall as a baseline layer of protection. This traffic-filtering function serves as a critical first line of defense against unauthorized access attempts, helping to block known malicious traffic patterns and prevent external attackers from directly reaching vulnerable internal systems. Understanding the firewall's role as a rule-based network traffic gatekeeper is foundational cybersecurity literacy relevant to both personal computer safety and broader organizational network security.

Data backup correctly helps protect against loss of data due to hardware failure, malware, or accidental deletion, ensuring that important files remain recoverable even when the original source becomes damaged, corrupted, encrypted by ransomware, or otherwise inaccessible due to unforeseen circumstances. Hardware components like hard drives can fail unexpectedly regardless of careful maintenance, while accidental deletions and malware attacks represent additional common threats to data integrity that no amount of careful usage can completely eliminate. Best practices for backups often include the '3-2-1 rule,' recommending three total copies of important data, stored on two different types of media, with at least one copy kept off-site or in the cloud, protecting against various different failure scenarios simultaneously. Establishing a consistent, automated backup routine is one of the most fundamental and cost-effective cybersecurity practices individuals and organizations can adopt to safeguard against potentially devastating and irreversible data loss.

The purpose of software patches or updates from a security perspective is correctly to fix security vulnerabilities that could be exploited by attackers, addressing newly discovered weaknesses in software code that, if left unpatched, could allow malicious actors to gain unauthorized access, execute harmful code, or otherwise compromise a system's security. Software developers and security researchers continuously discover new vulnerabilities in existing software, releasing patches to close these security gaps before attackers can widely exploit them, though a window of vulnerability inevitably exists between a flaw's discovery and its eventual widespread patching. Promptly applying security patches, whether for operating systems, applications, or firmware, is considered one of the single most effective and fundamental cybersecurity practices, since delaying updates leaves known, exploitable vulnerabilities exposed for longer than necessary. Understanding patches as targeted fixes for specific security vulnerabilities helps explain why prompt, regular updating is consistently emphasized as essential cybersecurity hygiene.

Cybersecurity broadly refers correctly to the practice of protecting systems, networks, and data from digital attacks, encompassing a wide range of technologies, processes, and practices designed to defend computers, servers, networks, and the sensitive data they contain from unauthorized access, damage, theft, or disruption. This broad field includes numerous specialized subdomains, such as network security, application security, information security, and incident response, all working together to address the constantly evolving landscape of digital threats facing individuals, businesses, and governments alike. Cybersecurity has become an increasingly critical concern as more aspects of daily life, business operations, and government services have moved online, making digital systems attractive targets for financially motivated criminals, state-sponsored actors, and other malicious parties. Understanding cybersecurity as this comprehensive, multi-faceted protective discipline is foundational to grasping the countless more specific security concepts and practices that fall under its broad umbrella.

A data breach is correctly defined as an incident where unauthorized individuals access confidential data, occurring when sensitive information, such as customer records, financial details, passwords, or proprietary business information, is accessed, stolen, or exposed by someone without proper authorization, whether through hacking, insider threats, or accidental exposure. Data breaches can have severe consequences for affected organizations, including significant financial losses, legal liability, regulatory penalties, and lasting reputational damage, while also potentially exposing affected individuals to risks like identity theft or financial fraud. High-profile data breaches affecting major companies have become increasingly common news stories in recent years, highlighting the ongoing challenge organizations face in adequately protecting the vast amounts of sensitive data they collect and store. Understanding data breaches as a serious, real-world cybersecurity consequence underscores the practical importance of the various defensive measures, like encryption, access control, and network security, that organizations implement to prevent them.