Firstly: I have found a number of questions answered that do everything but allow me to bypass UAC. I am IT for a small business, but it is not my primary responsibility.
I have two machines in my domain that on startup often fail to correctly connect to the domain network. Restarting the network adapter fixes the issue until the machine restarts. Unfortunately, one of the machines is used by a non-admin, and a technically illiterate one at that.
I hoped to use a powershell script to do this. Using this website, I created script and batch files to solve the issue. Since the computer only has one network adaptor, I went simple:
internet.ps1
Get-NetAdapter | Restart-NetAdapter
internet.cmd
#ECHO OFF
SET ThisScriptsDirectory=%~dp0
SET PowerShellScriptPath=%ThisScriptsDirectory%internet.ps1
PowerShell -NoProfile -ExecutionPolicy Bypass -Command "& {Start-Process PowerShell -ArgumentList '-NoProfile -ExecutionPolicy Bypass -File ""%PowerShellScriptPath%""' -Verb RunAs}";
Unfortunately, I don't fully understand the last command in the batch file. As such I struggle to research the command to pass some form of user credential. This environment is not very secure. But I don't want to give this user domain admin permissions generally, or provide them with some admin credentials which would end up on a sticky note. Either option is just inviting trouble from my older, technically illiterate colleagues. And going over to punch in credentials every day is time consuming.
I am looking for a script that cycles the network adaptor and provides the necessary credentials to make that change so a non-admin user can fix their domain and internet access without having admin credentials on a post-it note.
You could schedule a task using the Task Scheduler in Windows. When scheduling a task, you can specify credentials for the task to use when it runs. You can add a trigger for this task to have it run when the computer starts, or you can simply allow the user to manually start it.
If you decide to go this route, there is a check box you can check that runs the program with the highest possible privileges. The entire point of that last line is to start a new PowerShell window that runs as administrator so it actually has permission to restart the adapter. This means that you can get rid of almost your entire script, and just keep the part that actually restarts the adapter.
For example, when you go to create a new task in Task Scheduler, under the Actions tab, you can create a new action and enter the following:
Program/script:
PowerShell
Add arguments:
-Command "Get-NetAdapter | Restart-NetAdapter"
Note: I'm not sure if this is still the case, but in my past experience, sometimes it will try to run before Windows is fully loaded. If it doesn't seem to be doing anything on startup, you may need to add a delay to it. You can do this by running the Start-Sleep command. You can add it to the arguments field by doing the following:
-Command "Start-Sleep 5; Get-NetAdapter | Restart-NetAdapter"
Replace the number 5 with how many seconds you would like it to wait.
Related
I'm one of the IT admins in our company. Lately, cyber-security want to get stricter on how easily users can read and/or write data on USB sticks and external mass storage. In addition all new users getting new Windows notebooks will only have "non admin" permissions. All requests to install software etc must come through the IT desk.
An Active Directory OU has been created and some test notebooks have been assigned to it. My boss would like to me to write and test some Powershell scripts that would allow my colleagues and I (in a screen-sharing session with the user) to temporarily delete the registry keys that control USB storage access (until the next group policy update comes along). The hard part has already been taken care of. The intention is that script will be stored as a Nal-Object on ZenWorks, so the user would not be able to see the source code (kinda similar to an exe file that is just double-clicked on).
The code that is causing hassle...
# self-elevate to admin user - code at the very top of the PS file..
if (!([Security.Principal.WindowsPrincipal][Security.Principal.WindowsIdentity]::GetCurrent()).IsInRole([Security.Principal.WindowsBuiltInRole]::Administrator)) {
Start-Process PowerShell -Verb RunAs "-NoProfile -ExecutionPolicy Bypass -Command `"cd '$pwd'; & '$PSCommandPath';`"";
exit;}
# all the main code follows..
Here, if I run the script (in an non-admin account) I am prompted by UAC to enter the name and password of a local (or domain) admin account, a new window/session in PS opens and I can run whatever main commands need running.
The problem however is that is that when prompted for credentials and then type the correct password for a local non-admin account (as some users are inevitably going to do!) a new empty PS window/session just keeps opening indefinitely in a periodic fashion.
I've also tried adding an 'else clause' to the if-statement (to show an alert to the user and/or force quit Powershell, but it never seems to be get executed).
When I test this on a computer is that non part of any domain etc, I just get a "user is not authorised" kind of alert in UAC and no error gets the chance to propagate.
Is there any kind of workaround for this? It would be great too if the UAC prompt just defaulted to the name "ROOT\install". Nobody knows that password to this account except for IT admins.
I've also run Get-ExecutionPolicy -List... MachinePolicy and LocalMachine are "RemoteSigned", everything else is "Undefined".
I don't think execution policy plays a role in this strange loop, but I am open to being wrong. The script I am testing has not been through any signing procedures etc and is just sitting locally on the Desktop of one of the test computers.
Thanks.
Your symptom is mysterious; it implies the following:
The UAC prompt triggered by Start-Process -Verb RunAs mistakenly accepts a NON-admin user's credentials.
On re-entry into the script, the test for whether the session is elevated (!([Security.Principal.WindowsPrincipal] ...) then fails, and Start-Process -Verb RunAs is run again, at which point no UAC prompt is shown, because Start-Process does think the session is elevated and instantly spawns a new window.
The result is an infinite loop of new windows getting opened.
I have no idea what would cause this discrepancy - do tell us if you ever find out.
As workaround, you can try the following approach:
if (!([Security.Principal.WindowsPrincipal][Security.Principal.WindowsIdentity]::GetCurrent()).IsInRole([Security.Principal.WindowsBuiltInRole]::Administrator)) {
$passThruArgs = "-NoProfile -ExecutionPolicy Bypass -NoExit -Command `"cd \`"$pwd\`"; & \`"$PSCommandPath\`""
if ([Environment]::CommandLine -match [regex]::Escape($passThruArgs)) {
throw "You entered non-admin credentials. Please try again with admin credentials."
}
Start-Process -Verb RunAs PowerShell $passThruArgs
exit
}
# all the main code follows..
'Now running elevated...'
That is, the on re-entry the process command line is examined for containing the same arguments that were passed on elevated re-invocation. If so, the implication is that even though the UAC prompt accepted the credentials, the new session still isn't elevated, and an error is thrown.
Note that I've added -NoExit to the re-invocation, so that the new window stays open, which allows the results to be examined.
I am pulling my hairs as I could not figure out what happens in powershell on target machine task (v1.0 and 2.0) in my release.
every time I run the task, it throws me the error:
AuthorizationManager check failed. ---> System.Management.Automation.PSSecurityException: AuthorizationManager check failed. ---> System.Management.Automation.Host.HostException: A command that prompts the user failed because the host program or the command type does not support user interaction. The host was attempting to request confirmation with the following message: Run only scripts that you trust. While scripts from the internet can be useful, this script can potentially harm your computer. If you trust this script, use the Unblock-File cmdlet to allow the script to run without this warning message. Do you want to run \\server\c$\Program Files\exampleps.ps1?
I understand this may relate to execution policy, so this is what I have done so far trying to solve the issue:
I went in the remote server and turned off IE enhanced security for admins, as the service account to run this script is admin
Shift+Right-click powershell to run as service account and changed execution policy from remotesigned to bypass. performed this action in both 32 and 64bit powershell. Bypass was set to local machine and current user
Added the \server\c$\Program Files\exampleps.ps1 to trusted site under internet options
I have tried to google and stackoverflow similar questions and these are what I found.
Update
After trying all 3 methods above, even when I try to run the ps script directly in console, the security warning still shows up. For some reasons, the bypass execution policy doesn't kick in. --I was able to run it in console without warnings, however, tfs task still failed
I am really frustrated and I hope anyone in the community can give me some guidance on the this.
Much appreciated.
Please try the following ways to see if they can work:
Use the "Bypass" Execution Policy Flag
PowerShell.exe -ExecutionPolicy Bypass -File \server\c$\Program Files\exampleps.ps1
Read Script from the File and Pipe to PowerShell Standard In
Get-Content \server\c$\Program Files\exampleps.ps1 | PowerShell.exe -noprofile -
Use the Invoke-Expression Command
Get-Content \server\c$\Program Files\exampleps.ps1 | Invoke-Expression
Use the "Unrestricted" Execution Policy Flag
PowerShell.exe -ExecutionPolicy UnRestricted -File \server\c$\Program Files\exampleps.ps1
There also are few other ways you can try. To view more details, you can reference to "15 Ways to Bypass the PowerShell Execution Policy".
I've scheduled a batch file that has this command in a TaskScheduler and it never completes:
powershell -command "& 'C:\Test\CleanUp.ps1'"
The .ps1 file has a simple script that deletes files on different shares. The powershell script runs successfully when run in ISE or even the above mentioned command runs successfully when run at cmd prompt.
I've even tried the option below with the command and also searched a number of blogs but no luck.
-ExecutionPolicy Unrestricted
The task is scheduled to run with a service account and I've setup a number of identical jobs the same way and they worked fine. I have powershell version 4.0.
How do I get the job to complete? (successfully or with a failure)
I have seen this problem before and generally it turns out to be that, when running as a different user and/or with a different profile, the script hangs because it needs to prompt for input, e.g. a missing mandatory parameter, Get-Credential, or something like that.
I'll assume that you have run the command from an interactive shell running as the service account, as this could reveal whether there is something different about the service account profile, etc. that may interfere with the running of the script.
I'll also assume that you have tried setting up the scheduled task with your own account, under which you know the script will run correctly.
Next, look at some of the other command line options for powershell.exe:
https://technet.microsoft.com/en-gb/library/hh847736.aspx
I'm not sure whether you'll get much mileage from the -ExecutionPolicy switch, as my experience is that people tend to set the policy to Unrestricted almost as soon as the server is commissioned and then never think about it again.
You might want to look at the -NoProfile switch, as that is something I see used quite often when calling PowerShell from a .bat file or directly in the task scheduler.
Notice the -File switch, which you might consider using instead of -Command.
I'm using a 3rd party monitoring service to restart services when they go down on various boxes. The 3rd party agent allows me to kick off an external program to do what I need. In this instance I've chosen powershell, and have a script that works fine. The problem is, when the 3rd party kicks off the script, it's always running it under the user Contoso\SYSTEM, so it can't do what it needs due to permissions. How can I force it to run under a different user? It calls the script by doing the following:
C:\Windows\SysWOW64\WindowsPowerShell\v1.0\powershell.exe -executionpolicy remotesigned -Command "C:\Scripts\test.ps1"
I can't figure out how to specify a different user in that line. Can anyone be of assistance?
Alright, so, I've been searching online forever, and I can't find anything on this at all.
Basically, what I want to do is run a program from an elevated PowerShell script, but I want the program to run as the standard user.
I need to do this because the program that I need to run requires access to a mapped network drive that the domain administrator accounts don't have access to. So, I basically need a line of code that will take the script out of elevated mode, or some extension to the Start-Program command that will make it run as the logged on user rather than the administrator account that the script is running from.
you could use psexec
psexec -l powershell.exe -executionpolicy unrestricted -noexit -file c:\temp\checkelevated.ps1
-l : Run process as limited user (strips the Administrators group and allows only privileges assigned to the Users group). On Windows Vista
the process runs with Low Integrity.
One way that I have used extensively in the past is to create a scheduled task on the fly specifying the currently logged user as the account that will run the task. The task would run some other script, command, etc. and it would occur in the context of the logged on user. This is possible by using Start-Process to call the schtasks.exe program that will...
Create the task (schtasks /create /tn "MyTask" /tr "powershell -file...." /ru "domain\username")
Run the task (schtasks /run /tn "MyTask")
Delete the task (schtasks /delete /tn "MyTask")
You would just need your script to get the current user, which can be done in a number of different ways. I've also put a 2 second pause in between those calls to schtasks just to ensure they all run.
There are more ways to do it (probably some even better) I guess, but this should also work.
If you need to run an executable or script under currently logged in user from an elevated environemnt, you can use RunAs with USERNAME environment variable passed as user argument:
runas /user:%USERNAME% program.exe
USERNAME environment variable should contain currently logged in user even in an elevated environment.
The generally intended and accepted way to do this is to specify the network UNC path instead of the network drive. You can even re-map the drive in the elevated process if you need it. That's how you're supposed to do it. If you have an account running a process that needs access to a network location, the proper answer is to grant that account the access it needs to do it's job.
However....
Does this or this or this describe the problem you're actually having? It's very unclear what you're trying to do. You've eliminated all context from your question.
If you're trying to run a script that needs to run elevated and needs to access the user's network drive and you can't use a UNC path for whatever reason, then the above three links are what you probably want.
If you really, truly need to impersonate a logged on user -- and I really struggle to think of a situation where I'd need to do this from a script -- then read on.
The alternatives that don't require knowledge of user credentials are:
Use a user logon script instead of a computer startup script. If necessary, grant the local user the permissions they need to run the rest of the script. I can't imagine you haven't thought of this already.
Create a scheduled task which runs as "Domain Users" or some other group that represents the users in question and the "Only run when logged on" is checked. Again, you'd need to grant the user the permissions they need to run the rest of the script, but it wouldn't tie you down to logon only.
Write a program which calls ImpersonateLoggedOnUser, which requires SeImpersonatePrivilege (Administrators have this by default, IIRC). These are native Win32 calls, not .Net, so they will not be straightforward to use in PowerShell. It's been about a decade since I've looked at this, and it used to be a huge pain because it would sometimes still prompt for credentials. I have to think that the increased security in Vista and later (UAC, et al) would have made this even worse. I also have no idea if you have access to mapped drives (i.e., if the impersonation survives network hops). I would choose this method approximately never.
For anything else, I think you will require credentials of the current user. What you'd be doing is credential hijacking, and OS security is specifically designed not to allow that.