Online Security

Viruses / Worms / Trojans


The word virus is often used to describe three different types of computer infections: worms, trojans and viruses. These are malicious programs that get installed on a computer, often without the knowledge of the user, and can lead to privacy being invaded and/or data being destroyed or corrupted on users’ hard drives.

These infections are primarily spread in the following ways:

  • Viruses: via e-mail attachments and file sharing
  • Worms: by being connected to the Internet without effective protection (read on for more info)
  • Trojans: by visiting corrupted web sites

Symptoms of Problems

Symptoms of an infected computer include:

  • Computer is unstable and crashing frequently
  • Slow Internet connection
  • You receive a call from your Internet technical support alerting you of the situation

Recommended Solutions

  • Install a virus-checking program, and keep it up-to-date. It is worth noting that some viruses will disable virus checkers and you may need to try a few different programs to find and remove an infection.
  • Install a firewall or router (with firewall built in).
  • Microsoft provides free support for virus and Trojan infection cleanup:


  • Do not open e-mail from sources you are not expecting
  • Do not open any attachments unless you are expecting the file
  • Have a good virus checking program that is kept up-to-date
  • Have a good firewall installed and running