Microsoft adds another layer of security, the IE9 SmartScreen Filter as a “SmartScreen File Checking” feature to Windows 8 to prevent malicious file downloads in Windows 8 Windows Explorer. Many users are annoyed by the User Account Control (UAC) feature in Windows Vista/7 and most people disable this feature intentionally, so Microsoft adds SmartScreen File Scanning feature for your next Windows operating system.
SmartScreen File Scan Feature in Windows 8
According LongZheng blog post “SmartScreen appears to serve two purposes – reactively scanning the file system and proactively preventing any downloaded applications that are not filtered from running. “
The SmartScreen File Scan feature will be enabled by default in Windows 8 and can be disabled in Folder Options.
IE9 SmartScreen Filter checks links users visit and file downloads against malicious links database and warns user when visiting malicious links/downloading suspicious files from Internet Explorer.