Yahoo Inc. and McAfee Inc. are joining to offer alerts about potentially dangerous Web sites alongside search results generated at Yahoo.com.

With the new security feature - slated to take effect Tuesday - people who search the Internet using Yahoo will see a red exclamation point and a warning next to links McAfee has identified as serving dangerous downloads or using visitors’ e-mail addresses to send out spam.

Dangerous downloads can include “adware,” which shows unwanted advertisements; “spyware,” which secretly tracks users’ keystrokes and other actions; and other malicious programs that can give criminals control over users’ computers.

Yahoo and McAfee hope the move will quell users’ anxiety about accidentally clicking on malicious links.