I work as a PC technician and I regularly encounter computers infected with viruses and spyware. To disinfect them, I have two choices: either install the anti-virus programs into the infected computer and then connect to the Internet to update them, or remove the infected hard disk and install it to another computer that has antivirus programs already installed.
Both options are quite time consuming, so I though of another way: Is it possible to install all AV programs on my 2GB Compact Flash, connect it through USB to the infected machine and then perform the scan? Do I need to install an operating system on the CF and boot from it?
Also, is the CF itself in any risk of getting infected? Can I somehow write-protect the CF?
The quick answer is yes. You could copy AV software to CF (be it Norton, Ad-aware, etc.) as either an installer or a runnable (I just made that word up) program and then execute it on the target machine. But you could just as easily burn the most recent, updated copy to a CD and do the same thing. What’s more, you can certainly make a bootable CD and circumvent any problems you had with boot-time viruses and their ilk. A CD carries no risk of infection (well, I’m not aware of any viruses that come with CD-burning technology…yet), though the CF itself should be relatively infection proof (well, safer than using a floppy, anyway).
If the AV program can run fully autonomously (i.e, no reg entries etc) you could install them and run them from the CF. I’d much more likely use a USB HD rather than CF. But, that’s a choice thing.
If the AV programs need reg entries, then you would need to either install them as you have been doing or boot an alternate OS as you suggest. Whether you can boot from the CF totally depends on your BIOS, however. I’ve not heard of a BIOS supporting USB boot. But, I’m probably behind the times in current PC technology being much more an enterprise server kind of guy.
Of course the CF is at risk of getting infected. Any viral code in memory or that gets executed while the CF is connected might infect files on the CF.
Trend Micro makes a free stand alone virus scanner (Sysclean) that uses the current virus pattern file. Just load Sysclean onto your CF, download the latest virus pattern release file into the same folder, plug it into the target computer and run Sysclean. It will create a scan log in the folder it is run from, so you might want to copy that whole folder to the target computer.