How does SmartScreen Filter help protect my computer from malicious or phishing websites?

Microsoft‌ SmartScreen Filter is a feature in Windows Internet Explorer that helps detect phishing websites and websites that distribute malicious software (also known as malware). Phishing websites are fraudulent sites that impersonate trusted or known websites to trick computer users into revealing personal or financial information. Malware websites distribute software that can attack your computer or steal your personal information.

While you browse the web, SmartScreen Filter runs in the background and (with your consent) sends the web addresses of the sites you're visiting to the Microsoft‌ SmartScreen service to be compared against lists of known phishing and malware sites. If SmartScreen Filter discovers that a website you're visiting is on the list of known malware or phishing sites, Internet Explorer will display a blocking webpage and the Address bar will appear in red. From the blocking page, you can choose to bypass the blocked website and go to your home page instead, or you can continue to the blocked website, though this isn't recommended. If you decide to continue to the blocked website, the Address bar will continue to appear in red.

To help protect your privacy, information that is submitted to the SmartScreen web service is transmitted in encrypted format over HTTPS. This information won't be used to identify, contact, or provide advertising to you. For more information on how Microsoft is helping to protect your privacy, read the Windows Internet Explorer 9 privacy statement.