operating-systems security malware
Definition
Malware
Malware (malicious software) is any software intentionally designed to cause damage to a computer, server, client, or network.
Types
Virus
Malicious code hidden within a legitimate program that replicates by infecting other programs. Requires a host to spread.
Worm
Standalone program that replicates and propagates over a network without requiring a host program.
Trojan Horse
Program appearing useful but containing hidden malicious code. Often downloaded voluntarily by the user.
Logic Bomb
Dormant code triggered by a specific condition (e.g., a date or missing user login).
Trapdoor (Backdoor)
Secret entry point bypassing normal security and access control mechanisms.
Attack Methods
Denial of Service (DoS)
Overloading a system so it can no longer provide its intended service.
Distributed Denial of Service (DDoS)
Coordinated DoS attack originating from many sources simultaneously.
Keylogger
Software recording keystrokes to steal passwords or sensitive information.
Buffer Overflow
Writing beyond buffer boundaries to overwrite the stack, potentially executing malicious exploit code by hijacking the return address.
Port Scan
Automated searching for open network ports to exploit known vulnerabilities.
Social Engineering
Using deception (e.g., phishing) to manipulate individuals into divulging confidential information.