Is the live CD malware-proof?

[Stevoisiak]

I know Ubuntu is a very secure system, but sometimes I may have to use Ubuntu temporarally on someone else's PC, or need to browse a virus-prone topic like free software.

My question is, if I am browsing with a Live CD, is it possible for any Malware, Viruses, Browsing History, or anything to infect anything on the host PC? If so, can this happen from normal browsing?

[H4F]

If you have official live cd. and didn't do any thinks during live cd install you should be 99% secure.

[Stevoisiak]

If you have official live cd. and didn't do any thinks during live cd install you should be 99% secure.
99% secure? What's the 1%? I need to know this before I can feel safe searching "Free Ringtones" from a live CD.

I know the CD can't get infected. But I'm worried about the host PC. And I don't mean installing the Ubunto OS. I mean running the Live OS from the CD. I'd use my USB Harddrive install, but that could get infected. Also, I would be using wine from the temp OS to test Windows EXE files.

[XCan]

The 1% (which probably is a lot less) is if someone runs a script mounts your drives and trashes them, since the livecd's sudo pass is known (none).

[H4F]

99% its just because nothing in this world can be 100% secure. You always have to measure the level of security you need.

[Stevoisiak]

Ok. Let me make a list here for what I'd want to know could infect the PC or not.

-Running a Windows virus in Wine
-Searching terms such as "Free Antivirus" in google without running any of the programs
-Running unknown Linux applications

Could any of these alter or effect a Windows Installation on a PC?

Obviously, I would not be as insecure as to purposly run virus's in Wine, or go to sites I know insecure, but I just want to know if a live CD is completly safe to use when testing unknown programs.
(I've already tested and found a legit free SWF image/music extractor)

[howefield]

-Running a Windows virus in Wine
-Searching terms such as "Free Antivirus" in google without running any of the programs
-Running unknown Linux applications

Could any of these alter or effect a Windows Installation on a PC?

Short answer is yes. Your first option could potentially cause damage. It may not be very likely but yes, it's possible.

Your only 100% secure way of doing what you want, I think, would be to disconnect the drives except for the optical one that you will use for the session.

[Stevoisiak]

Short answer is yes. Your first option could potentially cause damage. It may not be very likely but yes, it's possible.

Your only 100% secure way of doing what you want, I think, would be to disconnect the drives except for the optical one that you will use for the session.
Thank you. So just to be clear, If I browse the web, but dont install any applications, nothing can be infected?

[H4F]

"-Running unknown Linux applications"- let say if its a virus and it will run with enough permissions - 100% will be able to do trouble to your files.

P.S. May I suggest you to run everything in VmVare or Virtualbox. This will ensure 99% security to your machine from the treads you mentrion:

-Running a Windows virus in Wine
-Searching terms such as "Free Antivirus" in google without running any of the programs
-Running unknown Linux applications

[Trebaruna]

I'd recommend against a live session.
With a live session, you're very quickly running outdated software, in other words buggy stuff. Then again, it'd have to be a very specific attack against the live environment.

There's another option: start up a virtual machine and browse your shady topics there. Make a snapshot before you start and restore it after your done: if you've been infected it'll be gone, and it's impossible for it (unless you explicitly change it) to touch your drives.

Also, using the most recent version of Firefox and enabling addons like NoScript and FlashBlock really should provide a very decent level of protection.

EDIT: reading is a delicate skill; H4F also mentioned a virtual machine.

[lisati]

Running a Live CD is a good start, and most of the rest is being smart about what you open.