According to the F-Secure blog, Creative has reported it has accidentally shipped almost 4000 MP3 players with a Windows virus. This happened in Japan with the 5GB Zen Neeons players that have been shipping for two months now.
The file system on the players contains one file that is infected with the Wullik.B (also known as Rays.A) email worm. The worm won't infect PCs unless user browses the player files and clicks on the infected file.
The worm in case is over two years old and spreads by emailing copies of itself and dropping itself to shared folders.
Creative is reporting (in Japanese) that the virus affects players with serial numbers between 1230528000001 and 1230533001680.
View: Creative Press Release (Japanese)
View: F-Secure Weblog