The simplest way to protect your portable device from infection is to use a portable antivirus. The most robust portable antivirus solution is ClamWin, an open source anti-virus. However, ClamWin is not as good on performance and detection as some of its commercial counterparts. You will have to download regular updates, to make sure that the anti-virus is ready to tackle the latest threats. Also, ClamWin does not include any kind of on-access scanning, which means that you can take care of the virus problem only after the infection.
The portable version of ClamWin can be downloaded from portableapps.com. Once the installation client is downloaded, you will have to connect your portable drive to the computer. You will have to connect an external hard drive or other portable device at this point to the computer. Install the application, and select the portable location for installation. The application won’t appear in the Program Files listing, so every time you want to run it, you have to navigate to the portable device using Explorer, and manually click on the ClamWinPortable.exe file to start ClamWin up. The first time you start ClamWin, you will have to download and install the virus definitions. These help ClamWin stay up to date with the latest threats, and handle them. The first time this is done, it will take some time, depending on your internet speed. After the first time the updates are downloaded, subsequent definition updates take comparatively less time. Also, as ClamWin is a portable software, you can copy and paste the ClamWin folder in a number of portable locations, after the virus definitions have been updated.
Click on scan, and select the device you want to scan. This can include the device that you have the anti-virus in, or the host computer. Scanning will take some time, and then a report of all found threats will be posted on the screen.
There is a simple method for on-access protection, on any location with access to the internet. This however, requires you to be aware of the standard processes that run on the host computer. There is a tool known as Process Explorer. Process Explorer, is an alternative to the Windows Task Manager, with a few more nifty features thrown in. The advantage that Process Explorer has over Windows Task Manager is that you can pause troublesome processes instead of halting them. Many viruses, Trojans and worms are written in such a way that once the process they are running is closed down, they are immediately restarted. Process Explorer merely freezes these processes, with effect that they cannot do anything harmful, or spread to other devices. There is a portable version of Process Explorer, that can be taken around in a USB drive. Another alternative is to run Process Explorer live, from the internet, which can be done at http://live.sysinternals.com/procexp.exe.
This however requires a fair idea of the harmful processes that you have to watch out for and stop. Just head over to www.processlibrary.com, and you will get a good idea of what processes to watch out for. The most dangerous processes at any point of time are listed on the front page itself. You can search for suspicious processes, and find out why they are running, and what they are doing on the computer. Process Library also offers a small freeware utility that let’s you scan all the processes running on the computer for potential threats. This software is available at www.processlibrary.com/processscan. Once the scan is completed, the program communicates with the Process Library servers, and throws up a HTML page with the scan results. Look in the recommendation column for advice on what to do. If you want to rid the host computer of the viruses or worms, you will have to go ahead and use an anti-virus. However, if you merely want to safely use your portable memory, use Process Explorer to halt the processes that were alerted by the process scan, and proceed by plugging in the portable storage device.