Once downloaded, it secretly installs a malicious adware tool known in security circles as Hotbar.

FORBES: Scammers Roil The Internet In Wake Of Bin Laden's Death

In a report from IDC last month, the analyst firm described how hundreds of tests on pirate software sources showed that more than a third led to Trojans and malicious adware.

FORBES: When Criminals Exploit Apple's Own App Distribution System, What Hope Is There Of Stamping Out Piracy?

Although the numbers of computer viruses are growing every day, many makers of malicious programs have started putting their energy into creating so-called spyware and adware programs.

BBC: NEWS | Technology | Anti-spyware project helps users