[KB2563] How do I know if my computer is infected with a virus or other malware?


  • Determining if your computer is infected by a virus or malware

Symptoms may not be malware-related

The examples listed below are common symptoms of malware, but your computer may exhibit many of these symptoms for legitimate reasons unrelated to malware, such as software or hardware incompatibilities or system instability. 


Symptoms of malware affecting currently installed ESET products:

  • Your ESET product is disabled for no reason and cannot be restarted
  • A threat is discovered or the red ESET Threat Detected window keeps appearing
  • You receive frequent alerts from your ESET Personal firewall about an unknown program
  • You receive pop-up alerts from rogue antivirus programs claiming that you are infected with multiple viruses


Symptoms of computer malware that affect the internet:

  • You may receive the error "Internet Explorer could not display the page" when attempting to access certain websites
  • Your web browser (for example, Microsoft Internet Explorer, Mozilla Firefox, Google Chrome) freezes, hangs or is unresponsive
  • Your web browser's default homepage is changed
  • Access to www.eset.com is blocked
  • You get redirected to web pages other than the one you intended to go to
  • You receive numerous web-browser pop-up messages
  • Strange or unexpected toolbars appear at the top of your web browser


Malware symptoms that affect system performance:


Symptoms of malware in email:

  • You receive messages in your mailbox without a sender address or subject
  • People receive spam email from your email address with a third-party email program installed (for example, Microsoft Outlook, Outlook Express/Windows Mail, Windows Live Mail and Mozilla Thunderbird)

If you believe that your computer is infected with malware

Please see the following Knowledgebase article: