How To Set Powershell Execution Policy

Recently I was discussing with colleagues pop ways to bypass PowerShell's ExecutionPolicy restrictions. I realized that I had not gone through and blogged about these bypasses, and idea it would be a fun blog post for today. By default PowerShell is configured to foreclose the execution of PowerShell scripts on Windows systems. Which could prevent an engineer or programmer from running PowerShell scripts locally on their machines. PowerShell has get a target for many attackers because it is congenital into most machines, and 1 can alive off the land if you will. Past learning some common bypass methods it volition help an attacker or info sec professional person hop over this false protection policy.

What is the Execution Policy?

According to Microsoft, the execution policy is part of the security strategy of PowerShell. It determines whether you can load configuration files (including your PowerShell profile) and run scripts, and information technology determines which scripts, if any, must be digitally signed before they will run. Information technology should be noted that Microsoft has gone on record maxim that the ExecutionPolicy was never intended to exist a security control.

In order to change the PowerShell Execution Policy you take to first PowerShell as an administrator and run the following command Set-ExecutionPolicy -ExecutionPolicy RemoteSigned. You tin can also set the RemoteSigned to unrestricted, but information technology is discouraged past Microsoft.

Alright, but what if you lot are not an administrator yet? You lot have bones low privilege access to a Windows machine, and y'all need to upgrade your crush to something more stable, or to add some Empire persistence. How can you modify the ExecutionPolicy?

Viewing the Execution Policy

In order to get an idea of what the current auto or contour'south ExecutionPolicy is already set to we can simply run the following commands.

PS C:> Get-ExecutionPolicy

            Get-ExecutionPolicy -List | Format-Table -AutoSize

For testing I will be running a elementary control that will repeat "Hello, World" to the screen and launch the calculator executable. The commands below will be saved as exam.ps1 .

            Write-Host "How-do-you-do, World" calc.exe

For demonstration purposes I have run the examination.ps1 file to evidence that the ExecutionPolicy is electric current set to restricted.

In the 2nd screenshot, this is to demonstrate that I am running PowerShell as a low privilege user, and cannot set the ExecutionPolicy without elevating privileges.

Ways to Bypass Restrictions

Paste straight into the PowerShell Window (Alert: There is a length limit of a single command. 2047 or 8191 depending on O/S version).

two. Echo the Script and Pipe it to PowerShell Standard In

iii. Read Script from a File and Pipe to PowerShell Standard In

4. Download Script from URL (Remote and Local) and Execute with Invoke Expression

5. Use the Control Switch

6. Use the EncodeCommand Switch

seven. Use the Invoke-Command Command

8. Employ the Invoke-Expression Command

9. Use the "Bypass" Execution Policy Flag. In terms of Featherbed this might be the funniest ane, and best suited to show that Microsoft never meant for this to be a real security control.

10. Disable ExecutionPolicy past Swapping out the AuthorizationManager

xi. Gear up the ExcutionPolicy for the Process Scope

There are of course other means to perform the ExecutionPolicy Bypass, but hopefully this helps start to understand how piece of cake information technology is to side stride this restriction. Just a reminder to that Microsoft never intended for ExecutionPolicy to be a security control. Until next time!