PowerShell “Set-ExecutionPolicy” via the registry
Posted by jpluimers on 2019/07/10
I wrote about the PowerShell Set-ExecutionPolicy a few times before (links are below).
After writing those, I found out there is another value ByPass and that there are ways to perform this in the Registry not just for the local machine, but also for a user. In retrospect, that last observation is a bit obvious, but it can be really convenient if you want to change it for a different user than yourself.
For the machine and current user, these are the registry paths where Set-ExecutionPolicy will set the value of ExecutionPolicy to the desired enumeration string:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\PowerShell\1\ShellIds\Microsoft.PowerShellHKEY_CURRENT_USER\SOFTWARE\Microsoft\PowerShell\1\ShellIds\Microsoft.PowerShell
The trick is that you can set this for any user if you have their SID, which – for many known entities – you can get from [MS-DTYP]: Well-Known SID Structures via The mother lode of well-known SIDs – The Old New Thing.
So for instance, below are the users, keys and statements for the users under which most services run, so after executing the one for your target service, it can run PowerShell scripts:
LOCAL_SYSTEM:HKEY_USERS\S-1-5-18\Software\Microsoft\PowerShell\1\ShellIds\Microsoft.PowerShellLOCAL_SERVICE:HKEY_USERS\S-1-5-19\Software\Microsoft\PowerShell\1\ShellIds\Microsoft.PowerShellNETWORK_SERVICE:HKEY_USERS\S-1-5-20\Software\Microsoft\PowerShell\1\ShellIds\Microsoft.PowerShell
A command to set the value of ExecutionPolicy there to RemoteSigned is this:
::LOCAL_SYSTEM
reg add "HKEY_USERS\S-1-5-18\Software\Microsoft\PowerShell\1\ShellIds\Microsoft.PowerShell" /v "ExecutionPolicy" /t REG_SZ /d "RemoteSigned" /f
::LOCAL_SERVICE
reg add "HKEY_USERS\S-1-5-19\Software\Microsoft\PowerShell\1\ShellIds\Microsoft.PowerShell" /v "ExecutionPolicy" /t REG_SZ /d "RemoteSigned" /f
::NETWORK_SERVICE
reg add "HKEY_USERS\S-1-5-20\Software\Microsoft\PowerShell\1\ShellIds\Microsoft.PowerShell" /v "ExecutionPolicy" /t REG_SZ /d "RemoteSigned" /f
Related:
- [WayBack] PowerShell: the 2 most common error messages for starters
- [WayBack] Enabling powershell to run unsigned scripts for the current user only (via: Absoblogginlutely!)
- [WayBack] .NET/C#/PowerShell: building .NET DiscUtils library for virtual disk images
- [WayBack] PowerShell: fixing script signing errors even after you had “Set-ExecutionPolicy RemoteSigned”
- [MS-DTYP]: Well-Known SID Structures via The mother lode of well-known SIDs – The Old New Thing
- [WayBack] Set-ExecutionPolicy
–jeroen
The Wiert Corner - irregular stream of stuff 
Leave a comment