Has your anti-virus software blocked Scan2CAD from installing on your computer?
Anti-virus software does not work as an exact science. They make assumptions on what they identify fits within their parameters. These assumptions change as regular as multiple times a day (hence why anti-virus software requires regular updates.)
Rest assured that Scan2CAD is fully and extensively tested. It is secure and certified as such by the market leading software security certifier, Comodo.
To resolve you can simply tell your anti-virus software to ‘trust’ your Scan2CAD install or alternatively pause your anti-virus software during install.