Internet security firms on Tuesday issued a high-level alert to computer users about the spread of the "Worms_Sober.S" virus, which makes recipients believe they have won tickets to the 2006 football World Cup in Germany. Trend Micro placed the virus in its 'red alert' category, saying that "using social engineering techniques, it sends out an email supposedly sent by the soccer organization FIFA," offering tickets to the tournament. US firm McAfee classified the virus as a "medium risk," saying the e-mail message, written in German, "specifically targets German users." But Trend Micro and Panda Software said the virus could be spread in either English or German. Panda said it had attacked computers in Austria, Germany, Switzerland and the United States. The e-mail includes correct contact information for a FIFA official. A previous version of the "Sober" virus made users think that their private e-mails had gone to the wrong address, prompting them to open an infected attachment. World Cup organizers also warned online ticket buyers to beware of a virus embedded in an attachment telling them they have won places for next year's tournament. Fans have been warned not to open messages from Ticket@fifa.de or Gewinn@fifa.de.