When searching with Google, Yahoo, Ask.com or other search engines, clicking a paid link in a results page poses more than twice the danger than using an "organic" link said McAfee yesterday. Security vendor McAfee did concede, however, that the percentage of dangerous sponsored links has fallen in the past six months.

McAfee cited changes Google made last year to its AdWords paid link program as the reason behind the improvement.

"Organic search results have pretty much stayed consistent," said Mark Maxwell, senior product manager for McAfee SiteAdvisor, a free safe-browsing service.

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"But sponsored search has improved pretty dramatically," said McAfee's Maxwell

Sponsored links on search engines such as Google are paid for by online advertisers who hope to lead users from search results. Sponsored search links are still more likely to pose a risk, but things have improved.

In May 2006, SiteAdvisor reported that 8.9 percent of all paid links were potentially dangerous, whereas six months ago, that figure had dropped to 8 percent. Data from last month, said Maxwell, now pegs that number at 6.9 percent.

"That's largely attributed to Google taking several steps," he said. "It's been a little bit tougher on advertisers who want the prime spots on the page, and its association with StopBadware.org has also helped."

Google, along with other technology companies, such as Sun Microsystems and Lenovo, helped launch the malicious-site clearinghouse last year.

Because AOL and Ask.com also use Google's paid listings, the risk factor for their sponsored links also decreased. Only 4.4 percent of AOL's sponsored links, for example, were judged dangerous by SiteAdvisor last month, compared with 8.1 percent in November 2006 and 10.2 percent a year ago.

Modifications to Microsoft 's Live Search and Yahoo, however, were less successful. "With the exception of Microsoft, we've seen slight improvement across the board in organic search," said Maxwell, referring to nonpaid links.

Six months ago, 2.6 percent of Live Search's organic results were classified by SiteAdvisor as risky; last month the number had climbed to 3.2 percent.

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More of Yahoo's sponsored links, meanwhile, were dangerous in May than anytime over the past year. SiteAdvisor labelled 9 percent of Yahoo's paid links risky; in 2006, that figure ranged from 6.5 percent to 8 percent.

As it has before, SiteAdvisor's report also highlighted the most dangerous search keywords. Topping the chart were "bearshare", "screensavers" and "limeware", which returned risky links in ratios from 1-in-3 to almost 1-in-2. Other keywords to avoid, urged SiteAdvisor, include "kazaa", "wallpapers" and "ringtones".

"All of these keywords involve some code that the user is downloading," said Maxwell. "When they open that pipe to download something, it also opens up the pipe for a malicious site to download other things."

Not surprisingly, using adult search terms also remains a risky proposition. The fraction of risky sites found in adult keyword search results climbed from 8 percent last year to 9.4 percent today.

Clicking on a sponsored link displayed after an adult keyword search is even more likely to lead to problems, said SiteAdvisor: 23 percent of those paid links are to risky URLs.

"We're taking some baby steps," argued Maxwell. "I'd be thrilled if I thought the SiteAdvisor concept was dead. But it's not."

The May report is available on the McAfee site. Web safety plug-ins for Internet Explorer and Firefox are available for download.

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