Computer Science Test 3 Nddc Scholarship

Effective protection requires a three-tier approach: the software must be installed on the system, it must be actively running in the background to provide real-time scanning, and it must be regularly updated with the latest virus definitions to recognize newly created threats. Missing any of these steps leaves the computer vulnerable to modern malware attacks.

Stateful inspection, also known as dynamic packet filtering, tracks the operating state and characteristics of network connections traversing the firewall. It distinguishes legitimate packets for different types of connections. Only packets matching a known active connection are allowed through, which is much more secure than simple static packet filtering.

Clear text (or plaintext) refers to data that is in a human-readable form and has not been subjected to cryptographic transformation. If clear text is intercepted during transmission over a network, it can be easily read and understood by unauthorized parties, which is why sensitive information should always be encrypted.

A Discretionary Access Control List (DACL) is an internal list attached to an object (like a file or folder) in an operating system. It specifies which users or system processes are granted or denied access to that object. It is 'discretionary' because the owner of the object has the authority to control who has permission to access it.

Phishing emails often contain spelling mistakes and use generic greetings like 'Dear Customer' because they are sent to thousands of people at once. Legitimate organizations, such as banks, typically use your actual name and maintain professional standards in their communication. Checking both of these factors is a standard way to identify fraudulent messages.

Malware is short for 'malicious software.' It is an umbrella term that encompasses various threats designed to damage or gain unauthorized access to a computer system. The most common forms are viruses (which attach to files), worms (which spread across networks), and Trojan horses (which disguise themselves as legitimate software).

Packet sniffing involves using a software tool or hardware device to intercept and log traffic passing over a digital network. While network administrators use it for troubleshooting and monitoring, hackers use it maliciously to capture unencrypted clear text data, such as usernames and passwords, as they are transmitted between computers.

Signature-based detection works similarly to antivirus software; it looks for specific 'signatures' or byte sequences that are unique to known threats. This method is very effective at detecting established attack methods but is less capable of identifying brand-new 'zero-day' attacks that do not yet have an entry in the signature database.

Network Address Translation (NAT) is a method used by routers to map multiple private IP addresses within a local network to a single public IP address. This provides a layer of security by hiding the internal IP addresses of individual computers from the public internet, making it harder for hackers to target specific machines directly.

A digital signature is a mathematical technique used to validate the authenticity and integrity of a digital document or message. It provides the recipient with a strong reason to believe the message was created by a known sender (authentication) and that it was not modified in transit (integrity), providing non-repudiation.