Multi-scanning with VirusTotal Uploader
I've previously written about the new version of Process Explorer (here) that you can use to scan all running processes with 50 antivirus products. As great as that is, it uses the results of previous scans by others and doesn't re-scan the files.
To receive more up-to-date results you can use the VirusTotal Uploader (by VirusTotal/Google), although I prefer the VirusTotal Uploader by PhrozenSoft for a couple of reasons but mainly because you don't have to open a web page for each scanned file to see the scanning results. Really nice if you scan many files, for example all running processes.
Note: Scanning with this many engines increases the risk of false positives.