German football fans face an early invasion, before the World Cup torunament opens in their country next month - a Trojan horse masquerading as a downloadable tournament game plan.

The Baden-Württemberg State Bureau of Criminal Investigation (LKA) warned on Wednesday of an e-mail with a link to a self-extracting Excel file that claims to contain the game plan for the soccer tournament. The German-language e-mail contains the message "Fussball Weltmeisterschaft 2006 in Deutschland" (2006 World Cup Soccer Tournament in Germany) and the link "googlebook.exe."

When clicked, the link installs a Trojan horse on users' PCs, according to LKA.

The agency has informed Germany's Federal Office for Information Security (BSI) and, because the Trojan horse appears to have originated from a server in the US, the Federal Bureau of Investigation (FBI) as well.

LKA officials were unable to say whether an English-language version of the spam e-mail with the googlebook.exe is making the rounds.

The Trojan horse on the loose in Germany isn't the first attempt to trick World Cup soccer fans, nor is it expected to be the last to take advantage of an event of global interest.

Last year, the world's governing soccer body, FIFA (Fédération Internationale de Football Association), warned fans and others that its name was being abused in a global phishing scam.

Several lottery companies had sent unsolicited, official-looking e-mail around the globe, announcing that recipients had won a lottery and requesting personal data, including bank account information, for them to claim the prize money. The lotteries claimed to be organised on behalf of, or in association with, FIFA as well as the German organisers of the World Cup and their South African counterparts for the 2010 games.

Moreover, security experts including Mikko Hypp"nen, chief research officer for antivirus research at F-Secure Corp., are concerned that the soccer tournament in Germany could also be fertile ground for mobile phone viruses if last year's World Athletics Championships in Finland, are any indication.

Visitors to the athletic event in Helsinki not only had to brave wind and rain, but also face an outbreak of the Cabir mobile phone worm, which first surfaced in June 2004.