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Windows 10 password through Linux Live USB

Posted: Fri Oct 27, 2017 6:35 am
by ktl94
Hi all,

I'm a Linux newbie. Have been using dual booting Mint with the pre-installed Windows 10 for the past couple of months. All was fine until one fine day my friend remarked that he could bypass my Windows 10 password prompt simply by changing BIOS boot priority and live booting almost any Linux distro. He would have access to all my files stored on the local hard disk.

A little dazzled I tried to look online, but I couldn't find any method to stop any Linux live distro online. I was hoping I could get some help from the people on the forum.

A BIOS password won't help, as removing the CMOS battery for a minute would reset the BIOS.

The only good 'thing' in this scenario is should Windows ever crash, I have a safe way to recover all the files.

I'm sorry if I've asked a dumb question, and having gone through the forum rules I believe I've adhered to them all. If not, I'm sorry.

Thank you all for your help.

Regards,
Karthik

Re: Windows 10 password through Linux Live USB

Posted: Fri Oct 27, 2017 6:57 am
by ralplpcr
So I assume your question is "Can I do something to prevent a live Linux distro from accessing my Windows 10 partition?"

Short answer - no. But you can make it rather difficult.

As mentioned, a power-on password in the BIOs can be bypassed. But if your system supports it, you can use a hard drive password that tends to be a good bit more difficult to crack. It's similar to a BIOs password, except this one encrypts a portion of the drive in such a way that even if the drive is removed and dropped into another system, it won't mount. It's decryption "key" is tied to the specific hardware on which the password was generated. Of course, if you're dual-booting on the same drive then you still have to unlock the drive... so Linux can see it once you're booted into it.

Another thing you can do is to encrypt your drive. There are various ways to do this, from direct BIOs encryption to self-encrypting drives to third-party programs that will do the encryption. I can't comment as to which is "best" - - each has advantages & disadvantages, and your individual needs may differ from mine to determine what works for you.

A skilled forensic scientist has tools & methods where nearly any method can be bypassed. I'm not sure there is any way to protect your data so that someone wouldn't be able to read it with enough effort - - after all, it still needs to be accessible to *you*, and if it can be accessed, it can be cracked given enough initiative. But if you make it difficult, most casual snoopers won't bother - - and unless you have NSA-level secrets on your system or other illegal material, I suspect that should be more than enough.

Re: Windows 10 password through Linux Live USB

Posted: Fri Oct 27, 2017 7:55 am
by Mattyboy
Your friend is correct in saying that you can access all files including system configuration, anything on C: from Linux.

UEFI/Bio's are now set up to make this more difficult for people who don't know how to change a few settings, but remarkably easy all the same. You say you're booting Linux with Windows so should ( providing Windows is shut down correctly ) be able to access the drive from your file manager, as easy as clicking on the drive.

This all applies to 'Home' versions of Windows. Pay ( shocker ) Microsoft more money and you can buy the 'Pro' or 'Enterprise' editions which include the drive/file encryption program bitlocker, which you would then need to apply as encryption isen't set by default. This, of course, comes with its own worries whenever you encrypt a drive.

Only an idiot would keep sensitive files on a 'home' version of Windows.

You can't access a Linux drive from Windows, but you can access another Linux one, see encryption above.

Re: Windows 10 password through Linux Live USB

Posted: Fri Oct 27, 2017 10:41 am
by kukamuumuka
In Rescatux has a feature, which can set blank password in Windows 10. Basically it uses chntpw package.
A video about using chntpw -> https://www.youtube.com/watch?v=ffv7fw9HL7Y

Re: Windows 10 password through Linux Live USB

Posted: Fri Oct 27, 2017 10:51 am
by lmintnewb2
Agree with using an encryption app to selectively protect certain directories or whatever. Just my preference but don't do the whole disk encryption thing. Think it's more hassle and added overhead than it'd be worth and majority of what's on an OS really shouldn't be sensitive data anyway. Not to mention in the scenario you're talking about the person needs to a. Have physical access to your system plus the time taken to bother copying your data over b. Knowledge of gnu/Linux ... not overmuch but some required.

Re: Windows 10 password through Linux Live USB

Posted: Fri Oct 27, 2017 3:27 pm
by Mark Phelps
ktl94 wrote:Hi all,

I'm a Linux newbie. Have been using dual booting Mint with the pre-installed Windows 10 for the past couple of months. All was fine until one fine day my friend remarked that he could bypass my Windows 10 password prompt simply by changing BIOS boot priority and live booting almost any Linux distro. He would have access to all my files stored on the local hard disk.
Actually, if your Win10 setup is running with the default settings -- your friend is WRONG, as they are presuming that actions available historically are STILL available in Win10, which is sometimes NOT the case!

Both Win8x and Win10 introduced a new form of Hibernation which keeps the Windows filesystems mounted in Windows -- even when Windows is not running! The change in Win10, is that this function, known as Fast Startup (NOT to be confused with Fast Boot, which is different) is ENABLED. With this turned on, no Linux distro will be able to access your Windows filesystem because Linux will be denied permission to mount it -- since it is already mounted in Windows.

So, if you have NOT change this, which I suspect is the case, otherwise, you would have mentioned it, your files and folders in Windows are safe from being accessed by Linux (or, for that matter, even if booted from another Windows disk or USB).
The only good 'thing' in this scenario is should Windows ever crash, I have a safe way to recover all the files.
If, by this, you mean that you could use a Linux boot disk/USB to recover your Windows files -- WRONG -- for the same reason I mentioned above.

Re: Windows 10 password through Linux Live USB

Posted: Fri Oct 27, 2017 5:17 pm
by ralplpcr
Mark Phelps wrote:.... no Linux distro will be able to access your Windows filesystem because Linux will be denied permission to mount it -- since it is already mounted in Windows.....
If, by this, you mean that you could use a Linux boot disk/USB to recover your Windows files -- WRONG -- for the same reason I mentioned above.
I'll respectfully disagree. Mint contains the tools to un-mount your Windows partition, as well as turn off (erase) the hibernation file.

Please see this previous post for details.

Re: Windows 10 password through Linux Live USB

Posted: Fri Nov 10, 2017 4:59 am
by ktl94
Hi,
Both Win8x and Win10 introduced a new form of Hibernation which keeps the Windows filesystems mounted in Windows -- even when Windows is not running! The change in Win10, is that this function, known as Fast Startup (NOT to be confused with Fast Boot, which is different) is ENABLED. With this turned on, no Linux distro will be able to access your Windows filesystem because Linux will be denied permission to mount it -- since it is already mounted in Windows.
I checked to see if Fast Startup was enabled, and it was. I shut down the system and live booted through Mint Cinnamon, and still all my drives were mountable through Linux just by clicking on it. As mentioned by user "Mattyboy" I luckily run Pro version of Win 10. So I guess I'll just turn on BitLocker encryption. Still debating whether I should encrypt my whole HDD or just individual partitions.

Also just to clarify, I don't have any such secret files. They're mostly data sheets of companies which anyone can pull off the internet. And a few short stories. :P

But through they're not exactly secretive would still like to keep my data secure, and that's one big reason I chose Linux. As soon as my company gives me a work laptop, I'll convert my personal machine to Linux :)

Thank you all for your replies.

Re: Windows 10 password through Linux Live USB

Posted: Fri Nov 10, 2017 5:27 am
by catweazel
Mark Phelps wrote:Actually, if your Win10 setup is running with the default settings -- your friend is WRONG, as they are presuming that actions available historically are STILL available in Win10, which is sometimes NOT the case!

Both Win8x and Win10 introduced a new form of Hibernation which keeps the Windows filesystems mounted in Windows -- even when Windows is not running! The change in Win10, is that this function, known as Fast Startup (NOT to be confused with Fast Boot, which is different) is ENABLED. With this turned on, no Linux distro will be able to access your Windows filesystem because Linux will be denied permission to mount it -- since it is already mounted in Windows.

So, if you have NOT change this, which I suspect is the case, otherwise, you would have mentioned it, your files and folders in Windows are safe from being accessed by Linux (or, for that matter, even if booted from another Windows disk or USB).
Nonsense.

Re: Windows 10 password through Linux Live USB

Posted: Fri Nov 10, 2017 11:35 pm
by bob466
Very easy to mount Windows or Mint HDD with a live Mint Flash Drive/DVD. When you Boot to the live Flash Drive/DVD...plug in another Flash Drive and copy the files to it...easy. :D