Run ScriptBlock with different credentials - powershell

Question

I have a script, that determines a userid; once I have that userid, I want to run a script block against that userid using different credentials. Is this possible? Can anyone show me examples of this?

Answer 1

I got it, thanks to Trevor Sullivan for pointing me in the right direction. I ended up just putting my second ps1 file into a scriptblock, and running it as a job, and passing it the arguments from the main script, like this
$job = Start-Job -scriptblock {
param ($username)
some code to run against the variable that was passed in
} -Args $target -credential $Cred
$target being the variable I want to pass to my scriptblock.
$username being the parameter that the scriptblock accepts Thanks.

Answer 2

I know this was answered a long time ago, but I thought I'd add another option for those looking that returns data without having to retrieve it.
We can create a helper script that creates a pscredential and then uses it to start a local PSSession to run a script or scriptblock in a different user's context. You need to get the user password from somewhere, preferably entered as a secure string or retrieved from a Key Vault, but for the example our helper script will take it as a string parameter.
Script contents:
param ([string]$username,[string]$password)
$Username = 'username#domain.com'
$Password = ConvertTo-SecureString -String $password -AsPlainText -Force
$Credential = New-Object -Type PSCredential($Username,$Password)
$Session = New-PSSession -Credential $Credential
Invoke-Command -Session $Session -FilePath C:\Path\to\some\script.ps1
You can also use -ScriptBlock instead of -FilePath if you have a simple chunk of code to run or you have converted a script to a script block.
Hope this helps somebody out!

Answer 3

Security context for a session is established when the session is initialized. You can't arbitrarily run commands under a different context within the session. To run under a different security context (set of credentials) you'll need to initialize a new session under those credentials and run it there.
If you look at the help for Invoke-Command, you'll note that the -Credential parameter is only valid in parameter sets that specify a remote session by computername, uri, or session. You can also use -credential with Start-Job, which will run the command in a new session on the local machine.

Answer 4

This code will launch PowerShell in Administrator mode using the credentials provided and then run the code in the script block. There might be others ways but this works for me.
$account= # AD account
$password = # AD user password
$passwordSecure = ConvertTo-SecureString ($password) -AsPlainText -Force
$Cred = New-Object System.Management.Automation.PSCredential ($account, $passwordSecure)
$ScriptBlock = {
whoami
start-sleep 3
}
 
# Run PowerShell as Administrator with Custom Crednetails
start-Process powershell.exe -Credential $Cred -ArgumentList "-Command Start-Process powershell.exe -Verb Runas -ArgumentList '-Command $ScriptBlock'" -Wait