SAN FRANCISCO — An Internet arbitrator has awarded Google Inc. the rights to several Web site addresses that relied on typographical errors to exploit the online search engine's popularity so computer viruses and other malicious software could be unleashed on unsuspecting visitors.

The National Arbitration Forum, a legal alternate to litigating in court, sided with a Google complaint alleging that Sergey Gridasov of St. Petersburg, Russia, had engaged in "typosquatting" by operating Web sites named googkle.com, ghoogle .com and gooigle.com.

After former Stanford University graduate students incorporated the search engine in September 1998, Google registered its domain name a year later. Gridasov registered his Web sites in December 2000 and January 2001, according to Google's complaint.

In a decision made earlier this week, arbitrator Paul A. Dorf, endorsed Google's contention that the misspelled addresses were part of a sinister plot to infect computers with programs — known as "malware" — that can lead to recurring system crashes, wipe out valuable data or provide a window into highly sensitive information.

Gridasov didn't respond to Google's complaint, filed May 11, meaning the arbitrator could accept all reasonable allegations as true.

The Associated Press sent an e-mail yesterday to the address that Gridasov listed when he registered his Web sites. The response, which wasn't signed by Gridasov, acknowledged the misspelled names were adopted to attract more visitors, but said there hadn't been any complaints until the sites began posting code from another company, which assured it wouldn't cause any trouble.

F-Secure, a Finnish company specializing in identifying malware, identified googkle.com as a troublemaker in an advisory posted April 26 — nearly three weeks before Mountain View-based Google filed its complaint.

Trying to piggyback on the popularity of a heavily trafficked Web site isn't new. For instance, the address Whitehouse.com used to display ads for pornography was a surprise for Web surfers looking for Whitehouse.gov, the president's official online channel. Whitehouse.com now operates as a private Web site that sells access to public records.