Physical security = security

Papa, I cannot log into this old computer. I don’t have the administrator password.

I work in IT so I actually know better. It all started when my son came home with an old computer monitor from school on the last day before summer vacation. Why bring home old hardware? My boys shared an old tower computer but also shared an old laptop. It was only later I found out that there was a small bit of computer envy but could a single old monitor fix this situation?

Grandpa actually had gifted the boys an old computer some time back but we didn’t set it up. Only now months later did we discover nobody had the administrator password for the computer.

So we rolled up our collective sleeves and got to work.

Mounting NTFS partition

Password security is important but physical security is more important. I know this because we simply pulled the hard disk out, booted up Linux on another computer and reset the administrators password. Our first problem was mounting the hard disk.

The NTFS partition is in an unsafe state. Please resume and shutdown Windows fully (no hibernation or fast restarting), or mount the volume read-only with the 'ro' mount option

I had not experienced this exact problem before. Apparently Microsoft had made some changes about Windows 8 called fastboot which helped with the boot up speed. The downside is that this creates problems when mounting the partition.

Clean shutdown

I guess the big Microsoft knew that this might cause some sort of problems in some situations and has made it possible to do a clean shutdown in Windows 10, well perhaps in older versions as well. Do perform this clean shutdown simply hold the shift key down while shutting down the operating system.

It is possible to disable Fast startup in windows 10 under power settings. However, all I wanted was a clean shutdown and that was possible without even logging into Windows.

chntpw

I installed chntpw on my Linux machine.

sudo dnf install -y chntpw

Using the program was self explanatory, I simply choose to clear the administrators password. It actually took much longer to mount this NTFS file system than it did to clear the password.

I read a good blog about using chntpw program.

The most important take away from this experience is not that Windows 10 is a bad operating system. Of all the versions Microsoft has released Windows 10 does seem to be quite stable and reasonably intuitive to use.

However, this exercise has proven that physical access, well that coupled with unencrypted file systems makes it trivial take control over someone else’s hardware.

Live Linux DVD

The computer that we were working on was a tiny mini-pic without a DVD. However, this entire process is also just as easy using a USB stick with a bootable live image or a live DVD.

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