Top Ten Free Online Malware and Virus Scanners

if you feel your computer attacked by virus or malware, you can quick online check without having to install a client application. This few choices below provide a good alternative: Stay Tune!

BitDefender - Easy on-demand virus scanner using powerful BitDefender engines. It scans system memory, files and drive boot sectors. It also automagically cleans infected files. Uses ActiveX components (IE Only)

CA - Online virus scanner. Just agree to a little ActiveX component and you’re scanning with ease in just a brief moment. Uses ActiveX components (IE Only)
CA - Online Virus Scanner

ESET - Online malware scanner. With just an acceptance of ESET’s TOS, you can scan your PC for known malware including viruses, worms, Trojans, phishing, and spyware.

ewido - Simple cleaner for malware. Uses ActiveX components (IE Only)

F-Secure - Simple virus scan from web. Uses ActiveX components (IE Only)

Jotti - Simple file checker. Jotti uses several scanners to look into the file you upload to determine if it’s infected.

McAfee FreeScan - McAfee FreeScan is a great virus scanner using the award-winning McAfee Scan Engine. Uses ActiveX components (IE Only)

NanoScan - Great, fast scanning application previously covered by the MUO Directory.
NanoScan - Fastest Online Virus Scanner

Panda ActiveScan - Get a free Panda scan that checks for viruses, spyware and other various internet threats. Current count over 185,000 viruses, worms, and trojans. Uses ActiveX components (IE Only)

TrendMicro - Scans for Viruses and Malware. It also scans for vulnerabilities and and fixes them to prevent re-infestation.

source: http://www.makeuseof.com/tag/10-free-online-malware-and-virus-scanners/