echo cmd| command not working properly

Question

I am trying to run notepad.exe as user "blain". Therefore I would like to use the command runas /u:blain notepad.exe in command prompt, which works as expected and prompts for the user password. I would like to automate it, so, assuming blain's password is "pass", I type echo pass| runas /u:blain notepad.exe.

No matter what I replace pass with, the command always returns:

C:\Users\blain>echo pass| runas /u:blain notepad.exe
Enter the password for blain:
Attempting to start notepad.exe as user "BLAINE-WIN-10\blain" ...
RUNAS ERROR: Unable to run - notepad.exe
1326: The user name or password is incorrect.

An interesting thing to note is that the message appears instantly after pressing enter. If I manually enter the password wrong, it takes ~2 seconds to tell me it's wrong (giving the same error message).

Bali C · Accepted Answer · 2017-04-04 12:56:59Z

1

You can't pipe to runas, it's designed to not allow this.

https://blogs.msdn.microsoft.com/oldnewthing/20041129-00/?p=37183

You could try doing something similar in VBScript or Powershell though, if that's an option?

A VBScript option would be to send the keys to the console prompt, the password would have to be saved in plain text though:

Set WshShell = WScript.CreateObject("WScript.Shell") 
WshShell.Run "cmd /c runas /user:domain\user program.exe" 
WScript.Sleep 500 
WshShell.SendKeys "password" 
WshShell.SendKeys "{ENTER}"

A Powershell version, it will keep prompting the user until they get it right (save as .ps1, right click on the file and click Run with powershell):

Add-Type -AssemblyName System.DirectoryServices.AccountManagement
$ds=New-Object System.DirectoryServices.AccountManagement.PrincipalContext([System.DirectoryServices.AccountManagement.ContextType]::Machine)
for(;;)
{
    $cred=Get-Credential
    if($ds.ValidateCredentials("$($env:computername)$($cred.UserName)",$cred.GetNetworkCredential().Password))
    {
        #Success, start your program
        start program.exe -Credential $cred
        exit
    }
}

edited Apr 4, 2017 at 12:56

answered Apr 4, 2017 at 11:27

Bali C

31.4k37 gold badges128 silver badges155 bronze badges

Sign up to request clarification or add additional context in comments.

4 Comments

Blaine Over a year ago

bummer... My use-case kind of hinges on being able to pipe a password. It's an insecure method, but what I want to do is create an empty text file IF the user has entered their correct password

Bali C Over a year ago

@Blaine I'll see if I can come up with a VB solution, give me a few mins...

Blaine Over a year ago

Alright. I invited you to a chat if you want me to give you the whole backstory/requierments (a bit too long to post here)

Bali C Over a year ago

@Blaine Good, I've added another version, which should work much better

Collectives™ on Stack Overflow

echo cmd| command not working properly

1 Answer 1

4 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

4 Comments

Your Answer

Sign up or log in

Post as a guest

Related