As to Comodo Site Inspector, you can find more about it in its home page:
Including the online scanning service itself and a list of recent detections. The Comodo team describes the service as follows:
SiteInspector uses browser instance in sandboxed environment ( a virtual machine) and browses the page at the URL that you submitted. If the browser performs a malicious activity, crashes, downloads a suspicious file, changes registry entries or exhibits behavior consistent with malware activity then its flagged as malicious. This allows regular Internet users to test the safety of a particular website and allows website operators to test the safety of their website from their customers point of view.
SiteInspector acts as a vulnerable customer by visiting the page and testing whether it launches an attack. If it does, then the scan results will warn you that the website contains malicious content. Each scan takes only a few seconds.This description and other details can also be found in their FAQ.
We would like to give Comodo Site Inspector a really warm welcome and thank them for allowing us to keep improving VirusTotal!