So far, only a few copies of the worm have been found. It changes the Windows settings of infected machines to ensure that music and a copy of the game begin to play when the PC starts up. The worm then scours the network for other vulnerable computers and network drives.
"This worm puts up the Tetris game as a smokescreen as it tries to hop from computer to computer across your network," warned Graham Cluley, senior technology consultant for Sophos. "If your company has a culture of allowing games to be played in the office, your staff may believe this is simply a new game that has been installed – rather than something that should cause concern."
The advice is the same as ever: keep anti-virus software and firewalls up to date and do not open attachments to unsolicited e-mails.