ActiveVirusScan.com is a fake website where your computer will be scanned for potential threats. As you can obviously see this is fake and there is no scanning process on your computer. This is a social engineering trick to let you complete a survey and make money by selling your personal information from the survey. This information from the survey can also be used to subscribe you into a payed phone service, which costs you loads of money every week. Do not complete the Survey and close the website on detection.
It is advised to always read the Terms and Agreements before installing software on your computer. Do never click too fast thru the installation process [Next] button of software as you will agree to software you might not want to install. If the installer offers a Advanced or Custom option button, click it to find out if there is any other malicious software offered and installed during the installation process.