Vav-scan.com (http://scanner.vav-scan.com/) is the latest browser hijacker that belongs to Vista Antivirus 2008 rogue anti-spyware. This hijacker use trojan horse (usually Zlob Trojan) to install itself on your computer and generate fake spyware detection reports, show misleading online malware scanners. Vav-scan.com may slow your PC and change some system settings. We STRONGLY recomend to remove this scamware from your PC.
Here is the list of Vav-scan.com clone sites:

Vav-scanner.com
Vavscan.com
Vav-xscanner.com
Vav-x-scanner.com

Stay away from these sites!

Vav-scan.com Remover Download

Source: http://malware-remover.com/vav-scancom-scannervav-scancom-removal-tool/