Google has started warning users if they are about to visit a webpage that could harm their computer.
The warning will pop up if users click on a link to a page known to host spyware or other malicious programs.
The initiative comes out of a larger project cataloguing programs that plague people with unwanted ads, spy on web habits or steal personal data.
Google is one of several companies trying to act as an "in-flight advisor" to ensure people stay safe online.
The warnings will be seen by anyone using the search engine who clicks on a link to a site identified as harmful by the Stop Badware coalition.