If you keep up with technology, you likely have a flash drive or two at home for carrying files back and forth to work or school. They are extremely fast and convenient and can store tremendous amounts of data. You can easily copy files to a flash drive then work on them at school, work or even a friend's house. Until recently, there was not much risk in using a flash drive in more than one computer, but now things have changed.
In recent years malicious software programs have been independent, stand alone files. Whether you call them viruses or spyware, they were files that could be deleted. Sometimes anti-virus software could handle the task and other times the infections were so bad that a technician would have to manually remove them. Now there is a new breed of virus called Virut and other similar viruses may follow. Virut scans your computer for .exe, .scr, .asp and other file types. It modifies each one of them turning them into viruses. So, when it infects your calc.exe file, your Windows Calculator still runs, but it is now a virus itself.
Now here is the fun part. When you plug your flash drive into a computer infected with Virut, the files on your flash drive get infected immediately. Now plug your infected flash drive into a clean computer and it gets infected. Now imagine the computer you just infected is connected to a network at your office and the virus starts infecting files on that network.
This is what shutdown the computer systems at the City of Houston Municipal Courts a few months ago.
The recommended fix for Virut is to format your computer and start with a fresh clean install of Windows. We have not seen any of the most popular anti-virus software clean it. In fact, many of them can detect a Virut infection and will delete the infected files because they cannot heal or clean them. So if your computer is infected, all of your .exe (programs) files can get deleted when you run your virus scan. There is a free, but not so well known software called Dr. Web CureIt available at www.freedrweb.com that we have been able to clean some infected computers with.
The point I want to make is that it is no longer safe to plug your flash drive into just any computer and that you should be very cautious about others plugging potentially infected flash drives into your computer.