A new variant of the mass-mailing Sober worm is spreading across the internet, security experts have warned.
Sober.P, like other variants, uses a subject header in an e-mail to entice users to open an attachment that allows the worm to replicate itself via an infected user’s address book.
The worm can cripple corporate networks by the amount of traffic created by the mass-mailing that is created by infected machines.
McAfee, one of the security software companies tracking the worm, said it was using different e-mail headers for different countries. In Germany, where the football World Cup is being staged next year, the worm is promising free tickets to potential victims.
The worm has also been compressed to make it harder for anti-virus software to stop.