Introduction to Malware

Malware (Malicious Software) is any software intentionally designed to cause damage to a computer, server, or network.

Key Malware Types

1. Virus

• Requires a host program to attach itself to.
• Requires user action (like opening a file) to execute.
• Spreads by infecting other files on the host machine.

2. Worm

• Self-replicating and self-propagating.
• Does not require a host program or user action to spread.
• Often exploits network vulnerabilities to jump between machines.

3. Trojan Horse

• Disguised as legitimate software (e.g., a free game or utility).
• Once executed, it performs its intended malicious function (like opening a backdoor) while appearing benign.

Other Types

• Ransomware: Encrypts user data and demands a ransom for decryption.
• Spyware: Secretly monitors user activity (keyloggers, screen scrapers).
• Rootkit: Hides itself and other malware, maintaining persistent access.