Free Anti-Virus Software W32.Vote. Your own Web Site Internet etiquette Viruses and hoaxes Common links All external links will open in a new window Safe Internet browsing - how to protect against viruses. Viruses fall into the broad category of malicious program code. Most software is written to serve a useful purpose for the user, but programs have also been written that attempt to breach security, damage data, or display unwelcome messages. Most of the code in this very wide category is designed to achieve its goal by being executed by an unwitting user.
Viruses fall into the broad trojan horse category of malicious code.
What distinguishes viruses from other types of trojan horse is their ability to reproduce themselves. The converse is not true, of course, not all trojan horses are viruses. A password grabbing program is malicious and dangerous, but it cannot propagate itself. You will of course want to protect your system against all trojan horses, not just viruses. The most direct way to achieve this is for a virus to attach itself to a genuine executable program file such as an e-mail message or an Internet download.