Cyber criminals have hijacked legitimate web pages and abused search engine optimization (SEO) techniques in order to spread a rogue anti-virus program to unsuspecting users interested in a recent "Google Doodle," the small clip art that graces the search engine’s front page.

The Google Doodle in question was an Esperanto flag, celebrating the 150th anniversary of the birth of L.L. Zamenhoff, who invented the language. Clicking on the Doodle produced a slew of search results pointing to websites infected by malware, put there by malicious search engine optimization (SEO) tactics like keyword stuffing.

The malicious websites – some of which were compromised versions of legitimate sites – attempt to convince unwary web browsers to purchase fake anti-virus software by bombarding them with bogus alerts and fear-mongering pop-ups. In some cases, users are forced to enter credit card information in order to stop the deluge of fake alerts.

Computer security experts say that scareware scams like this one grew tremendously in popularity this year, proving themselves highly remunerative for online criminals and scam artists.