SearchScan is a free tool embedded into search
Yahoo is introducing new technology to its search engine which will warn users if they are about to click on a website that hosts viruses, spyware and spam.
SearchScan uses security firm McAfee's SiteAdvisor technology to warn users about "potentially risky sites".
The service, which is switched on by default, produces an on-screen alert.
"Our goal is to protect users by allowing them to make a more informed decision about the sites they visit," said Yahoo's Priyank Garg.
Rival firm Google introduced similar technology in 2006.
Yahoo's service will warn users about three types of risk:
- Browser exploits: Sites that can harm a user's computer or install malware simply by visiting the site. Any such sites or pages included in McAfee's data will be removed from search results automatically.
- Dangerous downloads: SearchScan will display warnings next to search results for sites that offer potentially dangerous software, such as viruses, spyware or adware.
- Unsolicited e-mail: SearchScan will alert users to scanned sites that send unsolicited e-mails or inappropriately share e-mail addresses with third parties.
Viruses, spyware and adware programs are often "hidden" inside innocuous-looking programs such as screensavers and toolbars.
Industry analysts IDC estimate that 67% of all computers have some form of spyware installed without a user's knowledge.