Emails are one of the most popular ways of infecting any computer with nasty viruses. You have received an email with an attachment that you suspect is virulent. How do you check if it's a virus or not without having to download it? That's where VirusTotal comes to rescue.

VirusTotal provides free online virus scan against multiple virus engines, including BitDefender, ClamAV, McAfee and Symantec. Forward the suspected mail to scan@virustotal.com with SCAN as the subject of the email. Or, you can create a new mail, copy the link to the attachment file and send it to scan@virustotal.com with SCAN in the subject line.

VirusTotal will conduct a free virus scan of the suspected file and email you a report. It may take some time for the report to reach depending on workload. The file to be scanned can be up to 20MB.

If you have already downloaded the file, or have a suspect file on your computer, you can also upload the file at ViruTotal website for a free virus scan.