Kalkuhl is a senior virus analyst in Kaspersky Lab s Global Research & Analysis Team. He says multi-scanner based detection is just the symptom the root of the problem is the test methodology itself. Kalkuhl: In the end our task is to protect our users, not to hack test methodologies. The only way for them to classify the rest of their files is using a combination of source reputation and multi-scanners. This means that, like in the VirusTotal example above, every company that doesn t detect samples that are detected by other companies will look bad even if the samples might be either corrupted or clean.
Source: https://threatpost.com/way-better-malware-testing-020110/73461/