How to Use Claude Code for Reverse Engineering Like the Disney Infinity Modder

A developer just used Claude Code to crack a 13-year-old restriction in Disney Infinity 1.0 that the modding community couldn't solve for over a decade. The key wasn't just having Claude Code—it was using it with a specific reverse engineering workflow that you can apply to your own projects.

The Problem That Stumped Everyone

Disney Infinity 1.0 (2013) locks characters to specific "playsets" through code. Mr. Incredible can only play in the Incredibles world, etc. The restriction wasn't a simple flag—it was implemented through a single function (FindPlaysetForCharacter) called at 13 different points across 6 areas of the game's C++ code.

Previous attempts failed because:

• Patching one check didn't work (12 others still blocked)
• Data-file-only mods failed (native code validates before reading data)
• DLL injection crashed the game (thread-unsafe Lua state access)
• Renaming character files caused crashes

The Claude Code Workflow That Worked

The developer used Claude Code (Opus, high reasoning) with this exact approach:

1. Start with the Binary, No Source Required

# Open the game binary directly in Claude Code
claude code DisneyInfinity.exe --analyze

The key insight: You don't need source code or symbols. Claude Code can analyze raw binaries and help you trace execution paths.

2. Trace the Call Graph Systematically

Instead of trying to find "the fix," the developer had Claude:

• Identify the target function (FindPlaysetForCharacter)
• Trace every call site through the entire codebase
• Map which code area each of the 13 validation points belonged to
• Determine which checks were critical vs. redundant

3. Use Claude's Pattern Recognition for Assembly

When working with disassembled code, prompt Claude with context about the architecture:

I'm analyzing x86 assembly from a game binary. Here's a function that appears to validate character access. Can you:
1. Identify the validation logic pattern
2. Find similar patterns elsewhere in the binary
3. Suggest minimal patches that won't break other systems

4. Validate Each Patch Incrementally

After identifying patches, the developer:

• Applied them one at a time
• Tested game stability after each
• Used Claude to predict side effects before testing

Why This Workflow Succeeds Where Others Failed

Claude Code's Strengths for Reverse Engineering:

1. Cross-reference capability - Can find all instances of a pattern across millions of bytes
2. Architecture understanding - Knows x86, ARM, and common compiler patterns
3. Context preservation - Remembers the entire binary structure during analysis
4. Hypothesis testing - Can suggest "what if we patch this byte?" scenarios

The Critical Difference from Traditional RE:

Traditional reverse engineering requires manually tracing execution in a debugger for hours. Claude Code can:

• Map entire call graphs in minutes
• Identify redundant checks automatically
• Suggest optimal patch locations
• Predict crash points before they happen

Your Reverse Engineering Toolkit with Claude Code

Essential Commands:

# Analyze binary structure
claude code target.exe --analyze --output callgraph.json

# Search for specific patterns
claude code "Find patterns matching: 'cmp [eax+4], ebx'" --file target.exe

# Compare before/after patches
claude code --diff patched.exe original.exe

Prompt Templates for RE Work:

"I'm reverse engineering a binary that implements [system]. I've identified function at 0x123456 that does [purpose]. Find all callers and map the validation flow."

"Here are disassembly snippets from 3 areas of the binary. Identify common validation patterns and suggest which checks are primary vs. secondary."

"Propose minimal byte patches to bypass [restriction] without breaking [other functionality]. Consider alignment and relocation issues."

MCP Servers That Help:

• Binary Ninja MCP - Direct integration with Binary Ninja's analysis
• Ghidra Bridge - Connect Claude Code to Ghidra's decompiler
• Debugger Control - Interface with x64dbg or GDB

Lessons for Your Projects

1. Start with the hardest function - Not the easiest. Claude excels at complex pattern matching.
2. Map everything first - Don't patch until you understand the entire validation graph.
3. Use Claude's memory - Keep the conversation going. Each analysis builds on previous context.
4. Test incrementally - One patch, one test. Claude can help predict what breaks.

The Result: A Decade-Old Problem Solved

The developer's final solution: 13 targeted patches across 6 code areas, creating a universal character unlock that works without crashes. The modding community now has complete character freedom in Disney Infinity 1.0.

This isn't just about game modding. The same workflow applies to:

• Legacy system analysis
• Security vulnerability research
• Protocol reverse engineering
• Driver compatibility work
• Malware analysis

Claude Code turns reverse engineering from an artisanal craft into a systematic process. The Disney Infinity case proves that with the right approach, you can solve problems that have stumped experts for years.