Warning:

There are authentic branded USB flash drives as well as no-name knock-offs from 128MB to 1GB in size that have entered the discount store supply chain that contain Trojan viruses.

There are safety steps you can take.

I read a story about this, as well as infected-from-the-factory MP3 players as well. Keep in mind, some viruses can sit on a media of any type if they find nothing to infect or no internet connection and/or address book to work with. That is, until the infected media is inserted into a PC and away it goes like a kid in a candy store!

We had this happen at work with the main photo printer, which is PC-based and cannot run anti-virus software due to the co-OS of the maker being read as a virus.

We put in a CD-ROM from a customer, and sure enough, when they'd burnt it, they'd burnt a virus right along with their files to the CD and it took the printer down. Took me 2 days to get that $250,000 paperweight running again.

My recommendation is NEVER to insert your flash-drive or media into an unprotected computer...you might get something you don't want.

One time (a number of years ago) i was working on a clients computer. Hooked up his new digital camera, and we looked at pictures of his recent trip. Restarted the computer and when it came back up the pictures had been attacked by a virus. Did some looking around and found other jpgs on his drive that were gone as well. He had no anti virus! From then on I always checked for an anti virus and if it was updated. ...also he was unhappy and never heard from him again.

To prevent a virus from coming from a cd or thumb drive/usb flash drive you need to turn off the auto start routine. This way you get a chance to scan the drive or cd/dvd first for nasty things this will also prevent any hidden files (like on the music cd's) . The down side is you have to manually start those programs.