This document discusses various types of cybercrimes including software viruses, denial-of-service attacks, and phishing scams. It explains that viruses can infect computers and spread just like biological viruses, stealing or deleting files or allowing remote control of the computer. Denial-of-service attacks use compromised computers in a botnet to overwhelm websites with requests, while phishing scams trick users into sharing passwords or personal information through fraudulent emails appearing to be from legitimate sources. While technology aims to increase security, human errors remain the main cause of most cyber attacks.