Dilbert, the technoverse's personal hero, treats other users' USB drives like rats carrying fleas infected with bubonic plague. We sympathize: you don't know where that thing has been and what it might be carrying. The same is true if you carry a USB drive with important (maybe life-saving) data; you may be 100 percent sure your flash drive is virus-free, but can you say the same thing about the PCs you plug it into? No, and that's why you should have ClamWin Portable on your USB drive, CF card, or other high-capacity media. ClamWin Portable is the free, open-source antivirus solution portable-ized by Portable Apps, specialists in mobile freeware goodness.
We extracted the program's zipped download and saved it to a USB 2.0 thumb drive. With virus definitions, ClamWin Portable took up 56.6MB of drive space; once upon a time, that would be a lot, but it barely made a dent in our drive's 8GB of storage. The program downloaded an updated virus definition database as soon as we opened it. The compact main interface is extremely simple; it's essentially a window displaying our system's drives to select for scanning, a toolbar, and Scan and Close buttons. The toolbar accesses Preferences, Updates, and tools for scanning our computer's memory and selected files for viruses. We started with our USB drive by selecting it in the list and pressing Scan. The program displayed full file directories as it scanned; we could stop a scan, too, and save a report when it finished. ClamWin Portable's scans will probably take a bit longer than your main antivirus since it's running from a USB drive, but be sure you let it do its thing. The scan turned up a phishing scam, a spoofed e-mail domain in a year's-old mail archive file we keep around for just such a test. The report indicated the program scanned 1.16GB of data in 6 minutes, 10 seconds and flagged three issues. The memory scan took 1 minute, 26 seconds and flagged no files.
ClamWin Portable obviously isn't meant to be your main antivirus application. It's a precisely targeted tool that lets you apply up-to-date antivirus scanning and protection on the go. With it, you can take the tool to the threat instead of waiting for it to come to you.