Friday, 22 January 2016

Netac U335 write-protected USB 3.0 flash drive for E2B

Today I got my new 32GB Netac U335 USB 3.0 Flash drive with a write-protect switch.

The write-protect slide switch is ringed in red.

The drive is not the fastest USB 3.0 drive I have ever seen (33MB/s read, 14MB/s write on a USB 3.0 port), but if you need a reasonably cheap USB drive with a write-protect switch then this would fit the bill.
It is listed by Windows as 'OnlyDisk' and is of the normal Removable type.

It did not come with any string-loop for the keychain slot however, and the end cap cannot be fitted to the other end of the drive and so must be left lying around loose on the table whilst the Flash drive is in use (why don't they ever think of function versus looks?).

To write-protect it, you just slide the switch towards the USB connector (and vice versa to write-enable it). Much to my surprise, I found that Windows 10 would recognise the current WP switch state even if you changed the switch position whilst it was still connected to the PC - I did not have to remove the USB drive, switch and reconnect it each time - which was very handy! 

This means that you can quickly switch the USB stick to WP mode for any diagnostic use under a potentially infected OS.

You can boot from the E2B stick in Write-Enabled mode, boot to any ISO you like or use any .imgPTN file you like, start booting from it and then if you wish, move the switch to the WP position to safeguard it from infection or corruption whilst it is still booting!

This can be useful to safeguard the drive from accidental corruption. For instance, if you are installing an OS from the E2B USB drive, once it has booted to the install, you can write-protect the drive to prevent it from overwriting the boot sectors on the E2B drive instead of writing to the target drive (this can happen with some systems if you boot them by changing the boot order to boot from the E2B drive first, instead of using the BIOS Boot Selection pop-up menu to select the USB boot drive).

If you boot E2B in WP mode accidentally, you can move the WP switch to it's write-enabled position and then press F8 to reload the E2B menu for full write access.

The WP switch would also be hand for preventing my Windows Anti-virus scanner from deleting what it thinks are malicious files from the USB drive!

Using a WP drive with Easy2Boot

I made a few tweaks to E2B v1.77d, and now a write-protected E2B USB drive will be treated by E2B as if it had booted from a 'CD' drive.

This means that the menu entries for '0 Save defaults' and Fastload, etc. will not appear if the drive is in write-protect (CD) mode.

In addition, if you try to run any normal ISO file, E2B will try to automatically boot it using ISOBOOT because it cannot use the partnew grub4dos trick to write a new partition table entry to the USB drive.

E2B v1.77d now supports booting ophcrack ISOs via ISOBOOT (you need to extract the \TABLES folder onto the USB drive first). I downloaded and extracted both sets of tables from each ISO (XP and Vista/7) and then used the smaller 'notables' ISO for testing.

Here is the current list of ISO files supported by 'isoboot' in v1.77d (I haven't tested all of these in WP-mode yet though!):

  1. ubuntu
  2. linuxmint (linuxmint-cinnamone 17.1 64-bit 'Rebecca')
  3. fedora (not NTFS or exFAT)
  4. kali
  5. opensuse (not NTFS or exFAT)
  6. systemrescue
  7. knoppix
  8. debian
  9. tails
  10. gparted
  11. centos
  12. arch (user will be prompted for 32-bit or 64-bit boot, if dual ISO detected)
  13. zorin
  14. pclinux (not NTFS or exFAT)
  15. avg
  16. porteus 
  17. slax
  18. slackware 
  19. makulu 
  20. antix
  21. crunchbang
  22. acronis
  23. paladin
  24. Parted Magic
  25. Voyager (ensure the string 'ubuntu' is in the filename e.g. Voyager-14.04.04-amd64_ubuntu.iso)
  26. ophcrack - ensure \tables folder exists on E2B drive and use notables ISO (v1.77+)
Read more: http://www.easy2boot.com/add-payload-files/list-of-tested-payload-files/

This means that I should be able to boot any of these from the write-protected E2B USB U335 drive (in MBR mode - .imgPTN files require rd/wr access and so will not work in WP-mode).

XP installs from ISO should work, as do the memtest and FreeDos menu entries already in E2B.

Windows Vista/7/8/10 Install ISOs will give a 'Disk write error' because the \AutoUnattend.xml file on the flash drive cannot be updated:

Other Windows ISOs (e.g. WinBuilder, etc.) may also not work as expected (depending on how you have set them up on the E2B USB drive).

Of course, you can add your own .mnu files to boot your ISOs, as long as the grub4dos code does not use partnew or otherwise write to the USB drive.

I guess the most useful ISOs to use with WP would be anti-virus, repair ISOs and linux install OS's?