Yagnuul-A is an Excel formula virus that infects .XLS spreadsheets and then drops an infected fantasy league file on to the user's hard drive. The spreadsheet helps workers create their own fantasy football league with other fans of the English Premiership, which is made up of the best soccer teams in the country and has millions of followers based around the globe.
"Fantasy football-like leagues have been set up in offices across the country, and fans often keep track of how well they are doing by using Excel spreadsheets. Every computer user needs to take great care not to fall foul of malware like the Yagnuul virus or they will find themselves paying the penalty," said Graham Cluley, senior technology consultant for Sophos.
"This is a virus of two halves - one part infects your existing Excel spreadsheets, while the other drops an infected file onto your drive. Everyone should be careful about what files they open on their computer. You may think you are just re-using someone else's harmless spreadsheet, but behind the scenes a virus may be preparing to strike," he said.