A free online virus and malware scanner is available at http://www.virustotal.com
Simply upload a file and the web site will scan with over 30 different AV engines with a detailed report.
Great for scanning suspicious files, from unknown sources such as downloads from P2P networks or BT…
New: every file uploaded is now hashed with MD5 and reports are now saved for every file. If you submit a file that has been already scanned, you will have the option to bypass the scanning process and displaying the last report for the file.