McDonalds Japan and Coca Cola announced a contest in which flash MP3 players were awarded to contestants who submitted a unique winning number on a Coca Cola cup order at McDonalds. Ten thousand winners received the McDonalds-branded MP3 player preloaded with 10 songs and the QQPass spyware trojan. The trojan reportedly began to transfer username and passwords once it was connected to a Windows PC. Several reports claim that the trojan would take control simply by plugging the MP3 player into a Windows PC. Other reports, however, dispute whether or not that is how the trojan works.

An infected PC may be the original cause for all of the MP3 players being infected – McDonalds has declined to disclose what caused the original problem.

McDonalds Japan swiftly issued an apology while setting up a hotline to help users who were infected with the trojan. The infected MP3 players are being recalled while new MP3 players are being sent out to contest winners. McDonalds has also issued a statement informing contestants how to fix infected PCs.