Is it possible to contract a virus onto your windows hard drive when using a live cd? Say you visit the most infected site on the web that performs a dozen drive-by downloads, or if you insert a flash drive with a ton of infected files, could that some how find its way to your hard drive?

I know, I know, a lot of you are probably rolling your eyes at such a noob question.

Thanks for any replies. And sorry if it's been asked before; I did a search but nothing related.

Sure, it's possible. If you mount a hard drive, and explicitly copy and paste an infected file to the Windows hard disk, then it could be stored there. Of course, you'd have to click on it when you boot back into Windows (the executable won't run under linux most likely).

There are some cross platform malware types (javascript, etc) that theoretically could be passed from one OS to another, but I don't think there have been any seen in the wild.

Most linux machines are just carriers, i.e. you can drop an infected file somewhere and it won't activate until someone opens it under Windows.

Not a bad question at all, in fact a good question. Live cd's are still my favorite way to protect a system.

The cd may even have a virus.

Older live cd's never did mount the local hard drive in most cases. In time they tended to mount them more and more read only then at some point a lot of them mounted them read write. As above you have to watch out what distro you have an how it mounts local drives and if they are mounted read write. As with most live cd's they tend to be setup as root so any slip can be an issue. One would also have to watch any swap sort of file or persistent area or file.


A good choice for live cd would be one that didn't mount local hard drive at all or at least read only. Best if they require a password for you to perform a sudo. Most can be changed at boot.


Any time you are connected to the internet there are plenty of people out there trying to access your data. More so on those sites. Virus and other attacks can be automated and it may not matter which OS you have to what they may try to leave behind.

This depends on the involved pieces. The most complex and modern your OS is the greatest the chances to get an infection you will get because of a simple reason: modern desktops tend to do things behind the hood without you noticing it.

As long as your browser has the capabilities to store a file to your drive and the relevant disk is mounted (manually or via some desktop feature) all it takes to store the file is some kind of javascript (thanks we don't have activeX in linux, one less thing to worry about).

Of course, this depends on both the browser and how it is configured.

The chance however is that, as said, the malware will probably not run under linux. However windows has some autoplay features. I have no idea what the reach of the problem is, but a script that can store a file can also store contents on the autoplay scripts on the same device, so bear that in mind. I am no expert in windows at all but a file is just that, a file. If windows has autoplay turned then everything is possible.

A quick check with clamav from linux can reveal the menace before you plug the pen again on windows, preventing the whole problem.