This document provides an overview of different types of malware and security threats including viruses, worms, Trojans, spyware, phishing, spamming and spoofing. Viruses replicate by inserting copies of themselves into other programs. Worms replicate automatically to spread to other computers. Trojans contain malicious code that is concealed. Spyware collects users' data without their knowledge or consent. Phishing involves collecting data from legitimate-looking websites while spoofing involves falsifying documents. Spamming sends unwanted messages that may contain infected attachments. The document concludes by advising readers to use anti-virus software and respect copyrights.