This is a dropper ps1 script for Vidar
malware.
Variables are encoded after starting script, my guess is this way used for evading AVs.
Looking at the decoded variables, script's functionality can be guessed.



Now, Add-Exclusion is a function, that is used for defence evasion:

Start-Process, will start the C:\Users\<user>\AppData\Local\updater.exe
with Window Style hidden, Run as Administrator
option, and -Wait is used to suppresses the command prompt until the processes finish
.
finally
part is used to remove clean everything, leave a fake message to Host and finish script.
Continue: 9e126eb3b73eeae34c46a4b3dc9dc184a19708fd2b2433302c69e6c06b3929ed