A free Web browser that bills itself as a tool for privacy protection is, in fact, a click-fraud engine for pornographic Web sites, security vendor Panda Software warned Friday.

Browsezilla, whose name and Lizard-like mascot are reminiscent of the open-source Mozilla browser products, claims to help surfers cover their tracks when visiting pornographic sites. It does not use browser history or save data to a cache, and it allows users to save their bookmarks on a remote server, according to the product's Web site.

However, Browsezilla also secretly installs adware that boosts the page view counts on certain pornographic Web sites, said J.J. Schoch, director of marketing with Panda. "It's being used deceptively to get more hits on their site," Schoch said. "This adware opens a series of adult web pages, although they are not visible to the user."

The antivirus vendor issued a press release Friday warning of the browser, after noticing that Browsezilla was becoming more widely used. The browser is being used in a number of countries, but it appears to be most popular in Italy, he said.

Schoch said this is the first browser he has seen that downloads this type of click-generating software.

Panda is drawing attention to the matter because it believes the browser's creators are acting in a deceptive manner that ultimately could harm unsuspecting users, he said. "It's not going to wreck your computer, but it could taint somebody's reputation," he said.

Users might already be wary of the software, even without Panda's warning. The Browsezilla download page features an "Adult links" section with hard-core pornographic images, a rarity in browser download sites.

The Browsezilla team called Panda's allegations "unsubstantiated," on the Browsezilla.com Web site, but they shed little light on the situation when asked for further comment on Panda's press release.

"Thanks for references. There the full delirium is written. Yes, Browsezilla has unchangeable starting page http://browsezilla.org on which there is advertising. It is More than anything. We shall contact manufacturers anti-virus ON for finding-out," the browser-maker said in an e-mail note.