A web-search box was recently seen at the top of a Facebook page, indicating that the world's most popular social-networking giant is preparing to encroach into Web search giant Google's jurisdiction.

According to many, the web-search box at the top of a Facebook page is part of a beta testing of a new search feature.

But, Facebook has denied that it was testing a new search feature. Instead, it warned that those Facebook users who see the concerned web-search box might be infected with malware.

A representative for Facebook, said, "We believe the second search field or `Search the Web' box appeared on people's accounts as the result of unknown actions by a third party targeting the browser, potentially a browser plug-in or malware, unrelated to facebook."

The social network is already involved in search business to some extent. Previous fall, the company hit a deal with Microsoft to allow its Bing search engine to crawl its network for some results.

Saerch engine startup Blekko also uses Facebook's "likes" and other activities to produce some search results. But so far, Facebook is not involved in making searches itself.