Computer Viruses

Some Background

  • The vast majority of viruses target systems running Microsoft Windows.1
  • Often use complex anti-detection/stealth strategies are used to evade anti-virus software.
  • Viruses cause billions of dollars worth of economic damage each year.2
  • No existing anti-virus software is able to catch all computer viruses, the majority of products are unable even to guarantee 90% protection.3

How We Get Viruses

  • Websites – Never open links to web-pages that you don’t recognize or that are sent from people you don’t know. Malicious websites can install malware on your computer when you visit them.
  • Viruses target users browsing Internet websites, and rely on social engineering to deliver its payload. This infection is promoted through web sites that have been hacked with scripts that try to install the software by exploiting vulnerabilities on your computer. It is also promoted through Trojans that pretend to be legitimate programs that are required to view an online video, but instead it will install the virus.
  • Social engineering – Malware authors often try and trick you into doing what they want. This can be clicking or opening a file because it looks legitimate, paying money to unlock your computer or visiting a malicious webpage. These deceptive appeals are known as social engineering.
  • Website ad services can be infected. This means that visitors might get infected just by reading their favorite news site.4

Basic Steps to Prevent Infections

  1. Use up-to-date anti-virus software and use it to run frequent full-system checks.
  2. Make sure your operating system and browser are up to date.
  3. Be careful about what you download.
  4. Use an ad block extension for your Firefox or Chrome web browser (see my previous tech talk).
  5. Your everyday account should not have administrative privileges. Instead, create a separate administrator account to be used sparingly.

Available Tools

  • Malware Bytes
    An application for computers running under the Microsoft Windows operating system that finds and removes malware.
  • Microsoft Security Essentials
    An anti-virus software (AV) product that provides protection against different types of malware for home users for free.
  • VirusTotal.com, a Google product
    A website that provides free checking of files for viruses and can also scan suspect URLs.
    This can be used to scan email attachments before opening them.
  • Microsoft Safety Scanner
    Provides on-demand scanning and helps remove viruses, spyware, and other malicious software. It works with your existing antivirus software.
  • Microsoft System File Checker
    A tool to troubleshoot missing or corrupted system files on Windows.