Short but not sweet URLs

Compact versions of URLs (Web addresses), which online users can obtain from services that specialize in address shortening, are often used on social networks like Twitter to make it easier to post links.

No one can tell, just by looking at it, where a URL like bit.ly/16StNc will lead, so criminals sometimes use such addresses to mask malicious sites. (The one above, however, takes you to the home page of ConsumerReports.org.)

Last year, for example, some Twitter postings contained short URLs that linked to sites where people unwittingly downloaded malware called Koobface.

Things have improved since, says Morton Swimmer, a researcher for security software maker Trend Micro. "Short-URL providers have been very good at screening," he says. "I was skeptical at first, but none of my fears actually panned out in the long term."

But no safety net is perfect. To protect yourself further, we recommend that you use security software that includes a browser toolbar. That feature will alert you before you visit a risky site. Five security software suites we tested that have it are identified in the Ratings (available to subscribers).