Unit 4: AP Cybersecurity Vocabulary

Server

A computer or system that provides resources, data, or services to other computers (clients) over a network.

Embedded Computer

A specialized computing system built into a larger device to perform dedicated functions, such as in appliances or industrial control systems.

IoT

Internet of Things; network-connected physical devices that collect and exchange data, often with limited built-in security.

Virus

Malicious code that attaches itself to a legitimate file or program and requires user action to execute and spread.

Worm

Self-replicating malware that spreads across networks and systems automatically, without requiring user interaction.

Trojan

Malware disguised as legitimate or desirable software to trick users into installing it.

Ransomware

Malware that encrypts a victim's files or locks their system, demanding payment for restoration.

Spyware

Malware that covertly monitors and collects user activity or data without consent.

Keylogger

Malware or hardware that records a user's keystrokes to capture sensitive information like passwords.

Logic Bomb

Malicious code intentionally inserted into a system that lies dormant until triggered by a specific condition or event.

Rootkit

Malware designed to gain and maintain privileged access while hiding its presence from detection.

Fileless Malware

Malware that operates in system memory and leverages legitimate system tools rather than writing files to disk, making it harder to detect.

Cryptographic Hash

A one-way mathematical function that converts input data into a fixed-length string, used to verify integrity.

MD5 (deprecated)

An older cryptographic hash algorithm producing a 128-bit hash; no longer considered secure due to known collision vulnerabilities.

SHA-256

A cryptographic hash algorithm producing a 256-bit hash, widely used for data integrity and security.

SHA-512

A cryptographic hash algorithm producing a 512-bit hash, offering a larger output size than SHA-256.

NTHash

The hashing algorithm used by Windows to store password hashes in the SAM database, also known as NTLM hash.

Salt

Random data added to a password before hashing so identical passwords produce different hashes, defeating precomputed attacks.

Collision

When two different inputs produce the same hash output, undermining the integrity guarantee of a hash function.

Brute Force

A password attack that systematically tries every possible combination of characters until the correct one is found.

Dictionary Attack

A password attack that tries words from a precompiled list of common passwords or phrases.

Rainbow Table

A precomputed table of hash values used to quickly reverse-lookup plaintext passwords from their hashes.

Password Spraying

An attack that tries one common password across many different user accounts to avoid triggering lockout policies.

Credential Stuffing

An attack that uses lists of previously breached username/password pairs to attempt login on other services, exploiting password reuse.

BIOS / UEFI

Firmware that initializes hardware and boots the operating system; UEFI is the modern replacement offering enhanced security like Secure Boot.

Autorun

A feature that automatically executes programs from removable media upon insertion, historically exploited to spread malware.