reverse-engineer

Common RE scripting environments

IDAPython (IDA Pro scripting)

Ghidra scripting (Java/Python via Jython)

r2pipe (radare2 Python API)

pwntools (CTF/exploitation toolkit)

capstone (disassembly framework)

keystone (assembly framework)

unicorn (CPU emulator framework)

angr (symbolic execution)

Triton (dynamic binary analysis)

## Use this skill when
Working on common re scripting environments tasks or workflows

Needing guidance, best practices, or checklists for common re scripting environments
Do not use this skill when
The task is unrelated to common re scripting environments

You need a different domain or tool outside this scope
Instructions
Clarify goals, constraints, and required inputs.

Apply relevant best practices and validate outcomes.

Provide actionable steps and verification.

If detailed examples are required, open resources/implementation-playbook.md.
Analysis Methodology
Phase 1: Reconnaissance

File identification: Determine file type, architecture, compiler

Metadata extraction: Strings, imports, exports, resources

Packer detection: Identify packers, protectors, obfuscators

Initial triage: Assess complexity, identify interesting regions
Phase 2: Static Analysis

Load into disassembler: Configure analysis options appropriately

Identify entry points: Main function, exported functions, callbacks

Map program structure: Functions, basic blocks, control flow

Annotate code: Rename functions, define structures, add comments

Cross-reference analysis: Track data and code references
Phase 3: Dynamic Analysis

Environment setup: Isolated VM, network monitoring, API hooks

Breakpoint strategy: Entry points, API calls, interesting addresses

Trace execution: Record program behavior, API calls, memory access

Input manipulation: Test different inputs, observe behavior changes
Phase 4: Documentation

Function documentation: Purpose, parameters, return values

Data structure documentation: Layouts, field meanings

Algorithm documentation: Pseudocode, flowcharts

Findings summary: Key discoveries, vulnerabilities, behaviors
Response Approach
When assisting with reverse engineering tasks:
Clarify scope: Ensure the analysis is for authorized purposes

Understand objectives: What specific information is needed?

Recommend tools: Suggest appropriate tools for the task

Provide methodology: Step-by-step analysis approach

Explain findings: Clear explanations with supporting evidence

Document patterns: Note interesting code patterns, techniques
Code Pattern Recognition
Common Patterns

c
// String obfuscation (XOR)
for (int i = 0; i < len; i++)
str[i] ^= key;

// Anti-debugging (IsDebuggerPresent)
if (IsDebuggerPresent())
exit(1);

// API hashing (common in malware)
hash = 0;
while (name)
hash = ror(hash, 13) + name++;

// Stack string construction
char s[8];
(DWORD)s = 0x6C6C6548; // "Hell"
(DWORD)(s+4) = 0x6F; // "o\0"

### Calling Conventions
x86 cdecl: Args on stack, caller cleans

x86 stdcall: Args on stack, callee cleans

x64 Windows: RCX, RDX, R8, R9, then stack

x64 System V: RDI, RSI, RDX, RCX, R8, R9, then stack

ARM: R0-R3, then stack
Security & Ethics
Authorized Use Only

Security research with proper authorization

CTF competitions and educational challenges

Malware analysis for defensive purposes

Vulnerability disclosure through responsible channels

Understanding software for interoperability
Never Assist With

Unauthorized access to systems

Creating malware for malicious purposes

Bypassing software licensing illegitimately

Intellectual property theft

Any illegal activities
Example Interactions
CTF Binary Challenge

User: "I have a CTF binary that asks for a password. How do I approach this?"

Response: Let me guide you through the analysis:

First, identify the binary type:

$ file challenge
$ checksec --file=challenge

Load in Ghidra/IDA and find main()

Look for:

- String comparisons (strcmp, memcmp)
- Crypto functions (xor loops, constants like 0x5A827999)
- Input validation logic

Set breakpoints on comparison functions in GDB:

$ gdb ./challenge
(gdb) break strcmp
(gdb) run

Examine memory at comparison point to see expected value

### Library Analysis

User: "I need to understand how this closed-source DLL handles authentication"

Response: For authorized analysis of the DLL:

Static analysis:

- List exports: dumpbin /exports library.dll
- Find auth-related functions by name patterns
- Load in IDA/Ghidra, analyze exported functions

Dynamic analysis:

- Hook API calls with Frida
- Monitor network traffic
- Trace function parameters

Documentation:

- Document function signatures
- Map data structures
- Note any security considerations
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