TrevorC2 v2.1 releases – tunnels client/server communications for covert command execution

by do son · Published March 30, 2019 · Updated February 3, 2021

TrevorC2 – Command, and Control via Legitimate Behavior over HTTP

Written by: Dave Kennedy (@HackingDave) Website: https://www.trustedsec.com

Note that this is a very early release – heavy randomization and encryption to be added soon.

TrevorC2 is a client/server model for masking command and control through a normally browsable website. Detection becomes much harder as time intervals are different and do not use POST requests for data exfil.

There are two components to TrevorC2 – the client and the server. The client can be configured to be used for anything. In this example, it’s coded in Python but can easily be ported to C#, PowerShell, or whatever you want. Currently the trevorc2_client.py supports Windows, MacOS, and Linux. You can always byte compile the Windows one to get an executable, but preference would be to use Windows without having to drop an executable as a stager.

The way that the server works is by tucking away a parameter that’s right before the parameter. This is completely configurable, and it’s recommended you configure everything to be unique in order to evade detection. Here is the workflow:

1. trevor2_server.py - edit the file first, and customize, what website you want to clone, etc. The server will clone a website of your choosing and stand up a server. This server is browsable by anyone and looks like a legitimate website. Contained within the source is parameter that (again is configurable), which contains the instructions for the client. Once a client connects, it searches for that parameter, then uses it to execute commands.

2. trevor2_client.py - all you need in any configurable option is the ability to call out to a website, parse some basic data, and then execute a command and then put the results in a base64 encoded query string parameter to the site. That's it, not hard.

Changelog

version 2.1

* Added the cmd prompt library so that we have autocomplete on commands using tab as well as history (arrow up/down).
* — Also help is added to each command so you can type help (Also tab complete)
* Added servercmd as menu option to run commands on Trevor Server instead of ifconfig
* Converted agents into proper class objects and agentlistclass to add them into a userlist
* Updated the Readme.md

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