Pharming -a scamming practice in which code is installed on your computer, misdirecting users to fraudulent Web sites without their knowledge.
Real life incident: 2005 a website that attempted to redirect people to a web site selling pills.
Phishing -is the attempt to get personal information such as usernames, passwords, and credit card details, by sending an email claiming to be a legitimate enterprise so they can use the information for identity theft.
Real life incident: 2003 an email supposedly from eBay Sent to users saying there account would be suspended if they didn't click on a link and update their credit card details.
DOS attack-In computing, a denial-of-service attack (DoS attack) is a cyber-attack where the attacker seeks to make a machine unavailable to its users by temporarily or indefinitely disrupting the services that the host users.
Real life incident: - https://www.theguardian.com/technology/2016/oct/26/ddos-attack-dyn-mirai-botnet