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reversing-obfuscated-javascript

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Reverse engineer minified, bundled, and obfuscated browser/Node JavaScript — unpacking webpack chunks, recovering source from sourcemaps, undoing obfuscator.io string-array and control-flow obfuscation with webcrack/synchrony/restringer, and locating a signing or crypto routine in a live bundle via Chrome DevTools. Use when a page ships a huge minified bundle, when code is full of _0x hex identifiers and a rotated string array, when a .js.map is reachable, or when you must find where a request signature or token is computed.

secskills-core/skills/reversing-obfuscated-javascript/SKILL.md

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# Reversing Obfuscated JavaScript

Client-side JavaScript ships the whole program to the reader — there is no
stripped binary here, only code deliberately made unreadable. That changes the
job: you are almost never recovering *missing* information, you are undoing a
transformation. Identify the transformation first, reverse it with the tool
built for it, and fall back to hand-written AST passes only for the custom
layer no off-the-shelf tool knows.

## When to Use

- A page or extension ships a large minified/bundled `.js` you need to read
- Code is full of `_0x1234` identifiers, a big string array, and a rotation IIFE
  at the top — the obfuscator.io signature
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