restringer

Restringer

Deobfuscate Javascript and reconstruct strings. Simplify cumbersome logic where possible while adhering to scope limitations.

Try it online @ restringer.tech.

For comments and suggestions feel free to open an issue or find me on Twitter - @ctrl__esc

Table of Contents

• Installation
• Usage
  • Command-Line Usage
  • Use as a Module
• Read More
• TODO

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Installation

Requires Node 16 or newer.

git clone [e-mail]:PerimeterX/restringer.git
cd restringer
npm install

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Usage

The restringer.js uses generic deobfuscation methods that reconstruct and restore obfuscated strings and simplifies redundant logic meant only to encumber. REstringer employs the Obfuscation Detector to identify specific types of obfuscation for which there's a need to apply specific deobfuscation methods in order to circumvent anti-debugging mechanisms or other code traps preventing the script from being deobfuscated.

Command-Line Usage

Output deobfuscated result to STDOUT (nothing will print if deobfuscation failed)

node restringer.js script.js

Show debug information and save deobfuscated script to script.js-<obfuscation-type>-deob.js

export DEOBDEBUG=true && node restringer.js script.js

Log level can be adusted via the DEOBDEBUGLEVEL environment variable for more or less granular log output. The default level is an arbitrary 50, simply to leave space for other levels to be added when needed.

export DEOBDEBUG=true && DEOBDEBUGLEVEL=50 && node restringer.js script.js

Level 1 is most verbose, level 2 is a good value to use for debugging.

Use as a Module

const {REstringer} = require('restringer');

const restringer = new REstringer('"RE" + "stringer"');
if (restringer.deobfuscate()) {
  console.log(restringer.script);
} else {
  console.log('Nothing was deobfuscated :/');
}
// Output: 'REstringer';

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Read More

• Processors
• Tests
• Contribution guide
• Obfuscation Detector
• flAST

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TODO

• Replace environment variables with proper program arguments.
• Create binary tool that can be installed via npm install -g restringer