1. A virus is a small piece of computer code that can repeat itself and spreads from one computer to another by attaching itself to another computer file. One of the most common virus is Trojan.
2. Worms are self – repeating and do not require a computer program to attach themselves. Worms continually look for vulnerabilities and report back to the author of the worm when weaknesses are discovered.
3. Spyware can be installed on the computer automatically when the attachments are open, by clicking on links or by downloading infected software.
4. Ransomware is a type of malicious program that demands payment after launching a cyber – attack on a computer system. This type of malware has become increasingly popular among criminals and costs the organizations millions each year.