4 years ago I wrote up a thread (here at VirtualDr) on how to use a specially crafted autorun.inf file to help prevent computers from becoming infected by malware on a flash drive that had been used on an earlier infected PC. Since that point in time, the ability of computers to contract auto initiated infections from flash drives has changed a bit. Microsoft has either issued patches to older versions of Windows or released newer versions that do not automatically run USB drives. Patches for bugs in Windows that got around the autorun block were also issued since 2009 (Stuxnet used one of these bugs https://en.wikipedia.org/wiki/Stuxnet )


This all said, the thread I wrote offered no help in protecting the flash drive itself. Even if you use encryption on your flash drive, there is nothing to prevent the computer it's plugged into from infecting (or deleting file(s) from) it.

When flash drives were first released, there was a physical switch on many drives that could block the ability to write to the drive. (This was similar to the write protection floppy discs had available to them. USB flash drives replaced floppies.) But over time, for whatever reason, manufactures began to drop the write protect switches. To the point where I thought they were all gone.

But recently I learned (thanks to a thread at another website) that there are still a couple of manufacturers who make a few drives that have the switch. Those makers are Imation and Kanguru. In both cases, if you seek out the right models, you would have the ability to use a write protected USB flash drive on any computer (infected or not) and transfer files, cleanup tools, or whatever else and not have any changes made to your flash drive. Very handy!

At this point in time, here are the drives that I am aware of that offer a write protect switch. They should be available at several online merchants.

Imation
http://www.imation.com/en-US/Consume...p-Flash-Drive/

Kanguru
http://kanguru.com/storage-accessories/flash-blu2.shtml
http://kanguru.com/storage-accessori...guru-ss3.shtml
http://kanguru.com/secure-storage/de...sic-plus.shtml
http://kanguru.com/secure-storage/defender-elite.shtml

If anyone is aware of any other drives with write protection, please post in this thread so that others can also be aware of them.

I hope this helps!