German football fans have been complaining vociferously about the performance of their national team, recently humbled 4-1 by Italy, ahead of next month's World Cup. However, they've got problems of a different kind now in the shape of a Trojan, masquerading in a downloadable tournament fixture list.

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

When clicked, the link will install a Trojan horse on users PCs, according to LKA.

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

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

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

Last year, football's governing body, Fifa, warned fans and others that its name was being abused in a global phishing scam.

Several lottery companies had sent unsolicited, official-looking email 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 tournament.

Moreover, security experts including Mikko Hypponen, chief research officer for antivirus research at F-Secure, are concerned that the 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 the threat of catching the Cabir mobile phone worm, which first surfaced in June 2004.