What Is A Worm?

A worm is computer code that spreads without user interaction. Most worms begin as email attachments that infect a computer when they're opened. The worm scans the infected computer for files, such as address books or temporary webpages, that contain email addresses. The worm uses the addresses to send infected email messages, and frequently mimics (or spoofs) the "From" addresses in later email messages so that those infected messages seem to be from someone you know. Worms then spread automatically through email messages, networks, or operating system vulnerabilities, frequently overwhelming those systems before the cause is known. Worms aren't always destructive to computers, but they usually cause computer and network performance and stability problems.

 

What Is A Trojan Horse?

A trojan horse is a malicious software program that hides inside other programs. It enters a computer hidden inside a legitimate program, such as a screen saver. Then it puts code into the operating system that enables a hacker to access the infected computer. Trojan horses do not usually spread by themselves. They are spread by viruses, worms, or downloaded software.

 

What Is Ransomeware?

Ransomware, much as the name indicates, is a type of malware used to kidnap data. This type of malicious attack encrypts some or all of the files on the victim's computer, and the attacker then demands payment for the decryption key. Most ransomware infiltrates a victim's computer as would any other kind of malware — through infected programs, email attachments or malicious websites.