Trend micro
Housecall is a free online virus scanner offered by trend micro, which checks whether a pc has been infected by viruses, spyware, or other malware. housecall performs additional security checks to identify and fix vulnerabilities to prevent reinfection
http://housecall.antivirus.com/
Panda online scanner
panda online scanner
http://www.pandasoftware.com/activescan/com/activescan_principal.htm
Bitdefender
Bitdefender online scanner is an on-demand virus scanner which incorporates the award-winning bitdefender scanning engines. you can use it to scan your system's memory, all files and drives' boot sectors, and to automatically clean infected files.
http://www.bitdefender.com/scan8/ie.html