[HN Gopher] Unshackle: A tool to bypass Windows and Linux passwo...
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       Unshackle: A tool to bypass Windows and Linux password logins
        
       Author : AdvDebug
       Score  : 77 points
       Date   : 2023-07-20 10:54 UTC (12 hours ago)
        
 (HTM) web link (github.com)
 (TXT) w3m dump (github.com)
        
       | majkinetor wrote:
       | Title seems like some form anti-windows campaign while tool
       | clearly states its for both windows and linux.
        
         | pge wrote:
         | I had a similar reaction at first, but the title is accurate.
         | The tool only works on Windows. From the site:
         | 
         | >Tested on : >Windows 10 pro x64
         | 
         | >Linux bypass is still under development.
        
           | majkinetor wrote:
           | No its not, the title on GitHub is different.
           | 
           | It also states under Usage: Choose your OS (Windows or
           | Linux).
           | 
           | You can't say until using it which aspect of Linux support is
           | under development.
        
             | zokier wrote:
             | > You can't say until using it which aspect of Linux
             | support is under development.
             | 
             | Its not big project, you can pretty quickly browse through
             | the code and see that there is zero linux support
        
       | haspok wrote:
       | Seems to be from the Windows 7 era - doubt it will work at all on
       | later versions: https://superuser.com/questions/732605/how-to-
       | prevent-the-se...
       | 
       | ps. I stand corrected - probably something similar still works:
       | https://4sysops.com/archives/reset-a-windows-11-password-and...
        
       | agadius wrote:
       | Where's the source code for the binary file called "unshackle"
       | which is used in the solution? (This one:
       | https://github.com/Fadi002/unshackle/raw/main/unshackle)
        
         | codys wrote:
         | It appears to be a pyinstaller generated executable, presumably
         | we'd expect it to contain https://github.com/Fadi002/unshackle/
         | blob/main/src/unshackle..., but I haven't confirmed that.
        
       | Timwi wrote:
       | Hm, it says to press Shift 5 times on the Windows login screen.
       | By default this will enable sticky keys. Is that the intention or
       | is that a conflicting keybind?
        
         | dist-epoch wrote:
         | They replace the sticky keys executable with an exploit which
         | you trigger with the 5 x Shift key presses.
        
           | pjerem wrote:
           | Smart !
        
       | tallanvor wrote:
       | It requires physical access to the machine, which is always 95%
       | of the game. Plus, Bitlocker would prevent this from working, so
       | if you're using a recent computer and have Pro/Enterprise and
       | enable it, you don't have to worry about this attack vector.
        
         | CleanCoder wrote:
         | The limitations of this tool are obvious from the author's
         | documentation. Plus, a door lock would prevent this from
         | working, so if you're living in a recent house and have thick
         | door and lock the door, you don't have to worry about this
         | attack vector. It's strongly suggested to also hot glue your
         | USB ports shut for added security.
        
           | NoMoreNicksLeft wrote:
           | > It's strongly suggested to also hot glue your USB ports
           | shut for added security.
           | 
           | I don't see any reason to stop at _my_ USB ports. Take a hot
           | glue gun with you where ever you go, and glue them all shut
           | as soon as you find them. Help make the world a better place.
        
           | dotancohen wrote:
           | > It's strongly suggested to also hot glue your USB ports
           | shut for added security.
           | 
           | I'll just unplug your mouse / keyboard / wifi dongle and get
           | to the USB port that it's using. Unless you are suggesting
           | that modern computers should ship with zero USB ports.
        
             | 8n4vidtmkvmk wrote:
             | Jokes on you, I'll open the computer case and plug directly
             | into the mobo
        
               | jesprenj wrote:
               | You couldn't, the case cover is hot-glued to the case.
               | Hot-glue is the epitome of Windows security.
        
               | squarefoot wrote:
               | These days I would simply let the PC in the sun until it
               | melts all glue.
               | 
               | /s (not so much)
        
               | toast0 wrote:
               | All the cards should be hot glued into place, and any
               | extra connectors hotglued as well. The solution to not
               | enough hotglue is simply more hotglue!
               | 
               | > I'll just unplug your mouse / keyboard / wifi dongle
               | and get to the USB port that it's using. Unless you are
               | suggesting that modern computers should ship with zero
               | USB ports.
               | 
               | PS/2 is still available for mouse/keyboard (and secure).
               | Wifi dongles are abomination. Worst case, hotglue those
               | into the port.
        
       | tylergetsay wrote:
       | A cleaner imo solution is kon-boot which modifies the kernel on
       | windows/osx to disable password checking
        
       | catboybotnet wrote:
       | Neat, but replacing Utilman.exe with cmd.exe using most Linux
       | ISOs is easy, and I've already got the drives needed. The amount
       | of customers that get locked out of their servers...
        
         | shawnz wrote:
         | They actually recently made this attack vector more difficult
         | with a recent Windows Defender update:
         | 
         | https://security.stackexchange.com/a/176456
        
           | jesprenj wrote:
           | A trick I used that still worked after this Defender update
           | (tested some months ago) is replacing Magnify.exe with
           | ftp.exe. This does not make Defender suspicipus, but one can
           | open Magnify.exe from the lock screen and one can execute
           | commands from within the ftp.exe shell by prefixing them with
           | !. This is great, because ftp.exe binary is signed by
           | Microsoft and is a completely legit binary (:
        
       | user070223 wrote:
       | On a simlliar note: Has anyone succefully installed yubikey
       | windows 10(home) login for local accounts? They rereleased it for
       | windows 10 I think(version 2+), but it never worked for me
       | (apperently they relased a new version 2.11 recently for 11 &
       | 10(22h2 fix), which I haven't tried)
        
       | AdvDebug wrote:
       | Unshackle is a simple tool that deletes windows password logins
       | (Linux support coming soon) using a bootable USB Drive, and makes
       | you enter the system without any passwords, based on Alpine
       | Linux.
        
         | iso1631 wrote:
         | > Linux support coming soon
         | 
         | IF you're booting I used to use vim to just edit the shadow
         | file. Or simply passwd to set the password to something.
         | 
         | How does it cope with encrypted drives?
        
         | mrlinx wrote:
         | So you replace sethc.exe with what?
        
           | orthoxerox wrote:
           | A small C++ program that calls "net users" to erase or change
           | the password.
        
           | sunbum wrote:
           | [flagged]
        
       | BlackLotus89 wrote:
       | You can do the same thing without using a boot drive at all.
       | * Press F11 while booting       * open cmd in the rescue menu
       | * navigate to windows system32 folder       * rename sethc.exe to
       | sethc.exe.backup       * copy cmd.exe to sethc.exe       * reboot
       | and press at login 5 times shift       * add admin user       *
       | profit
       | 
       | Thing that is missing is password edit of online only accounts or
       | convert to local account
        
       | doubled112 wrote:
       | Its been a few years, but I used to use chntpw.
       | 
       | Has it stopped working?
        
         | abwizz wrote:
         | no and there are numerous alternatives.
         | 
         | idk why this made the frontpage other than beeing interesting
        
       | jaclaz wrote:
       | Only for the record, until it lasted (seemingly noone has been
       | interested in finding and updating the patterns to be patched or
       | maybe some other security measure was implemented in later
       | Windows 10) the "best" way (IMHO) was to patch a file.
       | 
       | Booting from USB with grub4dos, patching the .dll then continuing
       | booting and you could login as the original user but without (or
       | with "any") password:
       | 
       | http://reboot.pro/index.php?showtopic=18588
       | 
       | There are (were) derivatives to be run from a WinPE, but any hex
       | editor that could access the .dll would have done.
       | 
       | Let's say that it was a poor man's Konboot, that has (or at least
       | used to have) a similar approach, but patching files in memory.
        
         | guilamu wrote:
         | You can do that easily today with medicat (and ventoy).
        
           | jaclaz wrote:
           | Yep, but medicat lists (among other tools) the PEPassPass
           | (which is a derivative of PassPass), all those tools need to
           | boot into an Operating System (a PE or a Linux), change
           | _something_ , then reboot to the "normal" OS.
           | 
           | What is (was) elegant in the grub4dos PassPass is (was) that
           | you booted to grub4dos, ran the batch and then _continue_
           | booting to the  "normal" OS.
        
             | guilamu wrote:
             | Indeed, good point.
        
       | luma wrote:
       | Why does the title say "Windows" when the repo says "Windows and
       | Linux"?
        
         | ivann wrote:
         | Linux support is still marked as under development.
        
           | dsr_ wrote:
           | Which is a little strange -- since you have physical access
           | and are capable of booting from a USB stick, the procedure is
           | to tell the bootloader to use sh as the init, mount the root
           | filesystem r/w, change the root password (copying the hash
           | for later if you want to restore it), make sure it's written
           | to disk and reboot into the normal system -- only now you
           | have root.
           | 
           | If you have access to the bootloader's kernel command line,
           | you don't need the USB stick, either.
           | 
           | What this doesn't do is get you access to an encrypted
           | filesystem, unless the encryption password happens to be
           | written somewhere in the unencrypted partition. That happens
           | unsurprisingly often.
        
       | sgerenser wrote:
       | Doesn't windows use full disk encryption like macOS does these
       | days? How would you unencrypted the boot drive without the
       | password?
        
         | SamuelAdams wrote:
         | Windows Bitlocker is the FDE product that Microsoft uses. It's
         | not enabled by default. It is possible to have Bitlocker
         | disabled and password auth enabled.
        
           | 0cf8612b2e1e wrote:
           | At least on my corporate Windows laptop, the Bitlocker
           | password is restricted to numeric digits only. Coupled with
           | natural human laziness, and brute forcing looks fairly
           | feasible.
        
         | kekebo wrote:
         | There's Bitlocker but it's optional and has to be enabled by
         | the user.
        
           | m45t3r wrote:
           | There is also "Device Encryption"[1] that is separate from
           | BitLocker and works in any version of Windows 10/11 as long
           | TPM is available (and AFAIK is also turned on by default).
           | BitLocker is only available in the Pro versions.
           | 
           | [1]: https://support.microsoft.com/en-us/windows/turn-on-
           | device-e...
        
             | sgerenser wrote:
             | Amazing. Apple has had FileVault for _20 years_ (although
             | it's only in the past 9 years or so that it's been enabled
             | by default).
        
       | spydum wrote:
       | How strange, shouldn't windows be checking if the binary is
       | signed? Isn't that part of what secureboot and deviceguard do? Or
       | does it just run like any addon?
        
         | mr_mitm wrote:
         | Windows Defender started checking for modifications to binaries
         | like utilman.exe or sethc.exe a couple of years ago.
        
         | sim7c00 wrote:
         | secureboot could be leveraged for such things but as with most
         | great features, only the bare minimum implementation is
         | provided in 'modern secure operating systems'
        
         | aaronmdjones wrote:
         | Secure Boot only verifies the NT kernel loader; that in turn
         | will verify that the kernel is signed by Microsoft, and then
         | the kernel will verify any device drivers it loads. Userland
         | (e.g. explorer.exe) is free to be run without any signatures
         | whatsoever; this includes the login screen.
        
           | sim7c00 wrote:
           | its a shame they need to lean on defender for this. it
           | wouldnt be too long of a stretch to expect windows to verify
           | the binaries it ships with, and not accept unsigned ones for
           | those windows / MS binaries in the windows directory :(. it
           | does no justice to all the good that could be done via secure
           | boot
        
             | mr_mitm wrote:
             | We don't expect Linux to do this, do we? Just use full disk
             | encryption, preferably with pre-boot authentication. TPM if
             | you must, but this will only make the attack somewhat more
             | expensive. Other than that, the hardware is compromised as
             | soon as somebody gets their hands on it. Checking the
             | integrity of a few binaries is mostly security theater.
             | 
             | Besides manipulating executables, the adversary could
             | simply modify or read the user database in
             | C:\Windows\System32\config\SAM. [1]
             | 
             | Alternatively, patch routines directly in memory [2]
             | 
             | [1] https://www.kali.org/tools/chntpw/
             | 
             | [2] https://www.piotrbania.com/all/kon-boot/
        
               | the8472 wrote:
               | > We don't expect Linux to do this, do we?
               | 
               | Linux can be setup to verify an immutable userland via
               | secure boot + dm-verity. I think it's used in some google
               | devices (chromebooks?).
        
           | pjmlp wrote:
           | Still possible, as presented at BlueHat IL 2023, the goal is
           | to eventually have everything signed, based on how UWP
           | sandboxing is working, now extended to Win32 as well.
           | 
           | First set of changes already in flight for the next Windows
           | 11 stable release.
        
       | 0x53 wrote:
       | Recently I forgot my password to a laptop I didn't use much. It
       | was bitlocker encrypted, but I had saved the keys. So I booted
       | into a live Linux system mounted the bitlocker partition with
       | dislocker and then dumped the Sam hashes with impacket's
       | secretsdump. Then I used hashcat to try and crack my own password
       | since I thought I remembered parts of it. Ended up working!
        
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       (page generated 2023-07-20 23:02 UTC)