From iPods to navigation systems, some of today's hottest gadgets are landing on store shelves with some unwanted extras from the factory — pre-installed viruses that steal passwords, open doors for hackers and make computers spew spam.

Computer users have been warned for years about virus threats from downloading Internet porn and opening suspicious e-mail attachments. Now they run the risk of picking up a digital infection just by plugging a new gizmo into their PCs.

Recent cases reviewed by The Associated Press in an article on page M10 include some of the most widely used tech devices: Apple iPods, digital picture frames sold by Target and Best Buy stores and TomTom navigation gear.

In most cases, Chinese factories — where many companies have turned to keep prices low — are the source. So far, the virus problem appears to come from lax quality control — perhaps a careless worker plugging an infected music player into a factory computer used for testing — rather than organized sabotage by hackers or the Chinese factories.