Wednesday, January 7, 2015

Setting Backdoor in Windows | Command Prompt On Logon Screen

Lets assume that you have just cracked victim's windows password.  or simply got access to his windows for some time. Can you make some changes in windows so that you could access the windows again even if victim changes the password ?? or Can you make any changes in your own windows so that you could access it anytime even if anybody sets/changes password ?
Simply Can we set a backdoor in windows ?
Yes we can :) .
Backdoor actually means maintaining access.
okay lets do one thing first. Open your command prompt (run as administrator in win 7/vista).

Type the following command :

Syntax : net user *
Example: net user administrator *
and hit enter. Set any password for that account.

Hopefully your new password must have been set. did you notice one thing ? It didn't ask you to confirm old password. Now suppose if anyhow we manage to access command prompt at logon screen (without logging in), we can easily change/clear password.
Okay lets move on.
Now press shift key five times and you must have got a dialog box "sticky keys" on screen.

Sticky keys is a feature that makes it easy for users who have physical  disablilities to press multiple keys at time.   This is the only feature which can be used before logging in at logon screen ( as per my knowledge). I repeat this feature can be used at  logon screen by pressing shift key five times.
Whenevr we start an application like paint, we are actually running mspaint.exe placed in C:\windows\system32. or command prompt, we are running cmd.exe placed in system32 directory, similary
When we press shift key 5 times or use sticky keys feature, system actually starts the executable file
sethc.exe placed in system32 directory. This means if we rename cmd.exe to sethc.exe and press shift 5 times, system would again start sethc.exe but instead of sticky keys the command prompt will be opened.
But you just cant simply rename it or change system32 files. Follow the tutorial for that.

 Tutorial :

* Go to C:\windows\system32
* Copy cmd.exe on your desktop and rename it to sethc.exe .
*Now copy that file and paste again in system32 directory.

@ Windows XP Users

Hopefully existing orignal sethc.exe must have been replaced and your job is done. Now press shift five times and you would see command prompt on screen.You can access command prompt at windows logon screen and change/clear the password easily using "net user" command.

Note: You can also do these changes while using windows Guest Account. But when you would access command prompt at logon screen, you can change/clear password even of administrator's account. This is exactly how , we can hack into administrator's account through guest account.

@ Windows vista/7 Users

You must have got a pop up box saying "Access Denied".

Actually you can not change system32 directory files until you do not have the permissions. You can not have the permissions until you do not have the ownership. So lets take ownership, change permissions, just follow the steps.

1. Right click on sethc.exe and run as administrator.  Again right click on sethc.exe, open properties.
Click on Advanced tab , then on owner and click edit, change the owner from "trusted installer" to "administrator" and click apply.

2. Then click on 'Edit' in security tab to edit permissions. Click on 'Administrators' , give it full control
and apply changes.

Okay its done now.

Now try replacing the orignal sethc.exe with our sethc.exe (got by renaming cmd.exe).
Press shift key five times and hopefully you would get command prompt on the screen instead of sticky keys.

Enjoy Command prompt at logon screen...

So do not forget to set this backdoor whenever you would get friend's  laptop for a few minutes... :)

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