babel-plugin-deobfuscate

Implemented as Babel plugin. Written in TypeScript. Babel's core package "babel-core" and its helpers "babylon" (parser) and "babel-types" (AST) provide useful functions for AST manipulation. Babel is written in JavaScript. This allows some transformations to be implemented without the need to emulate JavaScript behaviour. For example, instead of emulating == expressions which is error-prone since they can result in surprisingly un-intuitive results, the expression can simply be evaluated on the de-obfuscator virtual machine. Because only JavaScript primitives are executed, this is not a security problem.

Given that Babel's core functionality involves transforming modern JavaScript, it is incentivised to keep the AST definition and the parser up-to-date with new language syntax.

Setup

First, install yarn.

# install dependencies and run tests
yarn install && yarn test
# build TypeScript sources
yarn build

Sources are found in src/; tests in test/. The test are a good demonstration of what this project does.

Terminology

Function Names

• evaluate: evaluate a given path or node and return an evaluated node.
• deobfuscate: evaluate a given path and replace it. Returns nothing!