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Deepsecrets - Secrets Scanner That Understands Code

By: Zion3R


Yet another tool - why?

Existing tools don't really "understand" code. Instead, they mostly parse texts.

DeepSecrets expands classic regex-search approaches with semantic analysis, dangerous variable detection, and more efficient usage of entropy analysis. Code understanding supports 500+ languages and formats and is achieved by lexing and parsing - techniques commonly used in SAST tools.

DeepSecrets also introduces a new way to find secrets: just use hashed values of your known secrets and get them found plain in your code.

Under the hood story is in articles here: https://hackernoon.com/modernizing-secrets-scanning-part-1-the-problem


Mini-FAQ after release :)

Pff, is it still regex-based?

Yes and no. Of course, it uses regexes and finds typed secrets like any other tool. But language understanding (the lexing stage) and variable detection also use regexes under the hood. So regexes is an instrument, not a problem.

Why don't you build true abstract syntax trees? It's academically more correct!

DeepSecrets tries to keep a balance between complexity and effectiveness. Building a true AST is a pretty complex thing and simply an overkill for our specific task. So the tool still follows the generic SAST-way of code analysis but optimizes the AST part using a different approach.

I'd like to build my own semantic rules. How do I do that?

Only through the code by the moment. Formalizing the rules and moving them into a flexible and user-controlled ruleset is in the plans.

I still have a question

Feel free to communicate with the maintainer

Installation

From Github via pip

$ pip install git+https://github.com/avito-tech/deepsecrets.git

From PyPi

$ pip install deepsecrets

Scanning

The easiest way:

$ deepsecrets --target-dir /path/to/your/code --outfile report.json

This will run a scan against /path/to/your/code using the default configuration:

  • Regex checks by the built-in ruleset
  • Semantic checks (variable detection, entropy checks)

Report will be saved to report.json

Fine-tuning

Run deepsecrets --help for details.

Basically, you can use your own ruleset by specifying --regex-rules. Paths to be excluded from scanning can be set via --excluded-paths.

Building rulesets

Regex

The built-in ruleset for regex checks is located in /deepsecrets/rules/regexes.json. You're free to follow the format and create a custom ruleset.

HashedSecret

Example ruleset for regex checks is located in /deepsecrets/rules/regexes.json. You're free to follow the format and create a custom ruleset.

Contributing

Under the hood

There are several core concepts:

  • File
  • Tokenizer
  • Token
  • Engine
  • Finding
  • ScanMode

File

Just a pythonic representation of a file with all needed methods for management.

Tokenizer

A component able to break the content of a file into pieces - Tokens - by its logic. There are four types of tokenizers available:

  • FullContentTokenizer: treats all content as a single token. Useful for regex-based search.
  • PerWordTokenizer: breaks given content by words and line breaks.
  • LexerTokenizer: uses language-specific smarts to break code into semantically correct pieces with additional context for each token.

Token

A string with additional information about its semantic role, corresponding file, and location inside it.

Engine

A component performing secrets search for a single token by its own logic. Returns a set of Findings. There are three engines available:

  • RegexEngine: checks tokens' values through a special ruleset
  • SemanticEngine: checks tokens produced by the LexerTokenizer using additional context - variable names and values
  • HashedSecretEngine: checks tokens' values by hashing them and trying to find coinciding hashes inside a special ruleset

Finding

This is a data structure representing a problem detected inside code. Features information about the precise location inside a file and a rule that found it.

ScanMode

This component is responsible for the scan process.

  • Defines the scope of analysis for a given work directory respecting exceptions
  • Allows declaring a PerFileAnalyzer - the method called against each file, returning a list of findings. The primary usage is to initialize necessary engines, tokenizers, and rulesets.
  • Runs the scan: a multiprocessing pool analyzes every file in parallel.
  • Prepares results for output and outputs them.

The current implementation has a CliScanMode built by the user-provided config through the cli args.

Local development

The project is supposed to be developed using VSCode and 'Remote containers' feature.

Steps:

  1. Clone the repository
  2. Open the cloned folder with VSCode
  3. Agree with 'Reopen in container'
  4. Wait until the container is built and necessary extensions are installed
  5. You're ready


Maldev-For-Dummies - A Workshop About Malware Development


In the age of EDR, red team operators cannot get away with using pre-compiled payloads anymore. As such, malware development is becoming a vital skill for any operator. Getting started with maldev may seem daunting, but is actually very easy. This workshop will show you all you need to get started!

This repository contains the slides and accompanying exercises for the 'MalDev for Dummies' workshop that will be facilitated at Hack in Paris 2022 (additional conferences TBA). The exercises will remain available here to be completed at your own pace - the learning process should never be rushed! Issues and pull requests to this repo with questions and/or suggestions are welcomed.

Disclaimer: Malware development is a skill that can -and should- be used for good, to further the field of (offensive) security and keep our defenses sharp. If you ever use this skillset to perform activities that you have no authorization for, you are a bigger dummy than this workshop is intended for and you should skidaddle on out of here.

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Workshop Description

With antivirus (AV) and Enterprise Detection and Response (EDR) tooling becoming more mature by the minute, the red team is being forced to stay ahead of the curve. Gone are the times of execute-assembly and dropping unmodified payloads on disk - if you want your engagements to last longer than a week you will have to step up your payload creation and malware development game. Starting out in this field can be daunting however, and finding the right resources is not always easy.

This workshop is aimed at beginners in the space and will guide you through your first steps as a malware developer. It is aimed primarily at offensive practitioners, but defensive practitioners are also very welcome to attend and broaden their skillset.

During the workshop we will go over some theory, after which we will set you up with a lab environment. There will be various exercises that you can complete depending on your current skillset and level of comfort with the subject. However, the aim of the workshop is to learn, and explicitly not to complete all the exercises. You are free to choose your preferred programming language for malware development, but support during the workshop is provided primarily for the C# and Nim programming languages.

During the workshop, we will discuss the key topics required to get started with building your own malware. This includes (but is not limited to):

  • The Windows API
  • Filetypes and execution methods
  • Shellcode execution and injection
  • AV and EDR evasion methods

Getting Started

To get started with malware development, you will need a dev machine so that you are not bothered by any defensive tooling that may run on your host machine. I prefer Windows for development, but Linux or MacOS will do just as fine. Install your IDE of choice (I use VS Code for almost everything except C#, for which I use Visual Studio, and then install the toolchains required for your MalDev language of choice:

  • C#: Visual Studio will give you the option to include the .NET packages you will need to develop C#. If you want to develop without Visual Studio, you can download the .NET Framework separately.
  • Nim lang: Follow the download instructions. Choosenim is a convenient utility that can be used to automate the installation process.
  • Golang (not supported during workshop):Follow the download instructions.
  • Rust (not supported during workshop): Rustup can be used to install Rust along with the required toolchains.

Don't forget to disable Windows Defender or add the appropriate exclusions, so your hard work doesn't get quarantined!

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Note: Oftentimes, package managers such as apt or software management tools such as Chocolatey can be used to automate the installation and management of dependencies in a convenient and repeatable way. Be conscious however that versions in package managers are often behind on the real thing! Below is an example Chocolatey command to install the mentioned tooling all at once.
 choco install -y nim choosenim go rust vscode visualstudio2019community dotnetfx

Compiling programs

Both C# and Nim are compiled languages, meaning that a compiler is used to translate your source code into binary executables of your chosen format. The process of compilation differs per language.

C#

C# code (.cs files) can either be compiled directly (with the csc utility) or via Visual Studio itself. Most source code in this repo (except the solution to bonus exercise 3) can be compiled as follows.

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Note: Make sure you run the below command in a "Visual Studio Developer Command Prompt" so it knows where to find csc, it is recommended to use the "x64 Native Tools Command Prompt" for your version of Visual Studio.
csc filename.exe /unsafe

You can enable compile-time optimizations with the /optimize flag. You can hide the console window by adding /target:winexe as well, or compile as DLL with /target:library (but make sure your code structure is suitable for this).

Nim

Nim code (.nim files) is compiled with the nim c command. The source code in this repo can be compiled as follows.

nim c filename.nim

If you want to optimize your build for size and strip debug information (much better for opsec!), you can add the following flags.

nim c -d:release -d:strip --opt:size filename.nim

Optionally you can hide the console window by adding --app:gui as well.

Dependencies

Nim

Most Nim programs depend on a library called "Winim" to interface with the Windows API. You can install the library with the Nimble package manager as follows (after installing Nim):

nimble install winim

Resources

The workshop slides reference some resources that you can use to get started. Additional resources are listed in the README.md files for every exercise!



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