Expert: Brian Benosky - 8/2/2009

Question
Hi Brian,

I have a general anti-malware question. I'm putting together a USB thumb-drive with various utils, including anti-virus and anti-spyware. I've got it to a stage where I'm happy with the software on it, but now I'm a little scared to plug it into an infected PC in case I just transfer the problem to the USB. Now, I know I can just image the thumb-drive and re-install it if necessary, but I was wondering what the chances were of malware transferring itself to my USB??

Many thanks,
Chris.

Answer
Hi Chris

Transferring viruses and other malware via USB has become increasingly common the past few years.  If you use your USB in unknown hosts, your chances of infecting the thumb drive is high.  First, you should enable write protection on the USB before you move it to an unfamiliar environment.  You can use the free utility found here to do that:
http://www.gaijin.at/en/dlusbwp.php
That should be enough to stop malware from entering the portable drive, but you can also go the extra step by disabling AUTORUN.INF on the drive, which will help to prevent spreading any infection.  See the program by Panda here:
http://research.pandasecurity.com/archive/Panda-USB-and-AutoRun-Vaccine.aspx
Finally, if you don't mind paying a bit, Naevius USB Antivirus is an excellent virus scanner that also provides the AUTORUN.INF protection.  There is a 21-day free trial, after which the cost would be $10US or 6.38 GBP.  Read about it here:
http://www.naevius.com/usb_antivirus.htm
Hope that helps.  Cheers!

Brian