Out-FINcodedCommand v1.0

Introduction

Out-FINcodedCommand is a PowerShell v2.0+ compatible PowerShell POC script designed to highlight several obfuscation techniques used by FIN threat actors. The primary obfuscation techniques highlighted in this tool are:

1. cmd.exe's variable char/string replacement functionality
2. cmd.exe and powershell.exe's StdIn command invocation capabilities
3. environment variable substring functionality to obfuscate "cmd" and "powershell"

Installation

The source code Out-FINcodedCommand is hosted at Github, and you may download, fork and review it from this repository (https://github.com/danielbohannon/Out-FINcodedCommand). Please report issues or feature requests through Github's bug tracker associated with this project. (Not really -- this is a simple POC, not a Cadillac with a warranty.)

To install:

Invoke-Expression (New-Object Net.WebClient).DownloadString('https://raw.githubusercontent.com/danielbohannon/Out-FINcodedCommand/master/Out-FINcodedCommand.ps1')

Usage

This is a simple POC so Out-FINcodedCommand is the only function that currently exists. Use Get-Help Out-FINcodedCommand to see available parameters.

You can approach this tool's obfuscation capabilities from the perspective of "blending in" a command to appear like a less conspicious "netstat -ano" or "ping 8.8.8.8" (like in the example screenshot above).

You can also take another approach to simply cram in as many confusing char/string substitutions as possible to make our jobs as Defenders more challenging.

Lastly, there is not support for CLI. Why? I'm too busy working on fun detection projects to spend on this. This tool is meant for education and not weaponization.

DISCLAIMER: Do not use this tool for evil. Please use this tool and its output responsibly and only on systems on which you have explicit permission to access and run obfuscated code.

License

Out-FINcodedCommand is released under the Apache 2.0 license.

Release Notes

v1.0 - 2017-07-02