Simple tools can extract hardcoded strings from the .rdata section, but that's trivial and not true decompilation.
In the niche but passionate world of indie software development, PureBasic holds a unique throne. It offers the raw speed of C with the "garbage-collection-free" simplicity of a structured BASIC dialect. Developers love it for creating lean, fast, and dependency-free executables.
However, this very efficiency creates a nightmare for reverse engineering. For every tool that claims to be a "PureBasic decompiler," developers and security researchers are asking the same question: Can we make this better?
The standard "PureBasic decompiler" tools available today are often outdated, fragile, or produce unreadable ASM-like pseudocode. This article explores what a "better" decompiler would actually look like, how it would function, and why you—whether a security auditor or a protecting your software—need to understand the difference.
A truly better PureBasic decompiler wouldn’t just dump assembly. It would reconstruct structured PB code with:
Tools like RetDec (open-source decompiler) can sometimes convert the x86 output of PureBasic to a higher-level intermediate language (LLVM IR). You then manually transcribe that IR to PB. This is tedious, but currently "better" than any dedicated PB tool.
To build or identify a "better" PureBasic decompiler, one must look for specific capabilities that move beyond standard static analysis.
A “better” PureBasic decompiler won’t appear out of thin air. But we can stop pretending the problem doesn’t exist. We can start documenting, start sharing small scripts, and ask Fantaisie Software to provide an official source recovery tool (even paid).
Until then, every time you compile an EXE and delete the source, you’re creating a future problem for yourself or someone else.
What’s your experience? Lost a PB source? Wanted to see how a certain library works internally? Or are you firmly against decompilation? Let’s discuss – but keep it constructive.
Posted in the spirit of better tooling for a great language.
To improve the quality of a PureBasic decompiler, you need to provide the tool with "symbolic" context to bridge the gap between machine code and high-level logic. Because PureBasic compiles directly to assembly (x86/x64) and lacks the extensive metadata found in languages like C# or Java, standard decompilation often results in unreadable code.
The following resources and data types are most useful for improving decompiler output: 1. Symbolic Information & Metadata
The most effective way to improve results is to import external definitions that help the decompiler identify known structures.
Function Prototypes & Names: If you have access to partial source code or official PureBasic .pbi include files, importing these helps the decompiler identify standard library calls rather than treating them as anonymous addresses.
Structures & Enums: Import PureBasic-specific structures (like RECT, POINT, or custom Structure blocks). Tools like Ghidra or IDA Pro can use these to "re-type" memory offsets into readable field names (e.g., *ptr\x instead of [eax+4]). 2. Library-Specific Knowledge
PureBasic relies heavily on internal libraries for Gadgets, Windows, and Graphics.
Standard Library Signature Matching: Using "FLAIR" (IDA) or "Function ID" (Ghidra) signatures for PureBasic’s static libraries allows the decompiler to label common commands like OpenWindow() or MessageRequester() automatically.
Inline Assembly Analysis: PureBasic allows inline ASM. A decompiler that can recognize common PureBasic ASM patterns (like its stack management) will produce cleaner output. 3. Open Source Tools & Frameworks purebasic decompiler better
Leveraging existing community projects can provide a better starting point for reverse engineering:
Awesome PureBasic: A curated list that includes disassemblers and documentation generators specifically for the PureBasic ecosystem.
PBasmUI: A specialized IDE tool for viewing and editing PureBasic assembly code, which is often the first step in creating a better decompiler output.
diStorm3 (PureBasic Wrapper): A high-speed disassembler library for x86/AMD64 that has been ported for PureBasic use, useful for building your own analysis engine. 4. Community Repositories
Analyzing how PureBasic handles complex logic in open-source projects can help you write better "lifting" rules (converting ASM back to PB logic):
PB-CodeArchiv-Rebirth: A massive collection of PureBasic code examples that can serve as a reference for how specific high-level commands look when compiled.
PureBasic Includes: A library of common helper functions and interface wrappers. ToniPB/distorm-PB - GitHub
Finding a Better PureBasic Decompiler: Tools and Strategies If you are looking for a "better" PureBasic decompiler, you have likely discovered that a one-click "EXE to PB Source" tool doesn't truly exist. PureBasic compiles directly to native machine code (x86, x64, or ARM). Unlike languages like C# or Java, which leave behind rich metadata, PureBasic strips away almost everything, leaving you with raw assembly.
To get "better" results, you must move away from looking for a specific "PureBasic Decompiler" and instead use professional-grade reverse engineering suites that handle native binaries. Why Standard Decompilers Often Fail
Standard decompilers struggle with PureBasic because of its unique compilation path. PureBasic can use an ASM backend (Flat Assembler) or a C backend .
No Variable Names: Once compiled, variable names like MyUserScore become memory addresses like [rsp+0x20].
Inlined Libraries: PureBasic statically links its massive set of 86 native libraries into your EXE. A decompiler sees thousands of lines of library code and has no easy way to distinguish them from your actual logic. "Better" Professional Alternatives
The following tools are considered the industry standard for decompiling native executables like those produced by PureBasic: Ghidra Decompiler Reconstructing C-like pseudocode from PB binaries for free. Ghidra Project IDA Pro Disassembler
The "gold standard" for professional analysis; includes the Hex-Rays decompiler. Hex-Rays x64dbg Real-time analysis of how a PB app handles data in memory. x64dbg RetDec Decompiler An open-source machine-code decompiler based on LLVM. RetDec GitHub How to Get Better Results (The Pro Workflow)
To improve your decompilation quality, follow this specific workflow:
Identify the Backend: Check if the binary was compiled with the ASM or C backend. The C backend often produces code that is slightly easier for tools like Ghidra to interpret as structured logic.
Use Function Signatures: To avoid getting lost in PureBasic's built-in libraries, use FLIRT signatures (in IDA) or Function ID (in Ghidra). These help the tool recognize standard PB functions (like OpenWindow() or MessageRequester()) and automatically label them so you can ignore them.
Recover Logic, Not Code: Do not expect to get .pb files back. Aim to recover the logic. Use x64dbg to set breakpoints on API calls (like User32.dll!CreateWindowExW) to find the entry point of your GUI code. Simple tools can extract hardcoded strings from the
Static Analysis: Use PBasmUI if you have the source and want to see how the compiler translates it. This helps you learn to recognize "PureBasic-flavored" assembly patterns. Is there a "PureBasic-Specific" tool?
While there is no "Magic Decompiler," some community tools can help: ghidra decompiler - freebasic.net
While searching for a "PureBasic decompiler" often leads to tools that claim to reverse-engineer executable files back into source code, the reality is that a perfect PureBasic decompiler does not exist
Because PureBasic compiles directly to highly optimized x86 or x64 machine code, the original variable names, comments, and structure are lost during compilation.
However, if you are looking for the "better" way to analyze PureBasic executables, here are the most effective tools and methods currently used by the community. 1. The Best "Decompiler": PureBasic's Internal ASM Output
The most accurate way to see what a PureBasic program is doing is to use the compiler's own ability to generate assembly code. How it works:
If you have the source code (or are testing your own app), use the /COMMENTED switch in the compiler. Why it's "Better": This produces a
file that includes the original PureBasic commands as comments above the corresponding assembly code. This is the only way to get a 1:1 map of PB logic to machine instructions.
2. Best for Reverse Engineering: Interactive Disassemblers (IDA Pro / Ghidra)
Since PureBasic produces standard executables, industry-standard reverse engineering tools are far superior to any "dedicated" PB decompiler. Ghidra (Free/Open Source):
Developed by the NSA, Ghidra is excellent at "decompiling" machine code back into a C-like pseudocode. While it won't give you PureBasic syntax, it will reconstruct the logic (loops, conditions, and function calls).
The gold standard for professional analysis. It has excellent signature matching that can sometimes identify standard PureBasic library functions (like OpenWindow MessageRequester ) within the binary. 3. Best for Debugging: x64dbg
If you need to see how a PureBasic app behaves while it is running, a debugger is more "readable" than a static decompiler. Function Identification:
You can often find the start of PureBasic procedures by looking for the standard stack frame setup. String Analysis:
PureBasic stores strings in a specific way in the data segment. x64dbg allows you to easily find these strings, which often reveal the program's logic and hidden commands. 4. Specialized Tool: PBDecompiler (Legacy)
There have been community projects specifically named "PBDecompiler," but they come with significant caveats: Limited Versions:
Most were designed for very old versions of PureBasic (v3.x or v4.x). Partial Recovery:
They usually only recover resources (icons, images) and some GUI structures rather than actual logic. Security Risk: We don’t need a miracle
Be extremely cautious downloading "decompilers" from unofficial forums, as these are common vectors for malware. Summary: Which is "Better"? For understanding logic: . It transforms the "messy" assembly into readable logic. For identifying PB functions: with PureBasic signatures. For your own code: Always use the /COMMENTED compiler flag to learn how your PB code translates to ASM. within a disassembled file?
Finding a "perfect" decompiler for PureBasic that returns original source code is virtually impossible because PureBasic is a compiled language. When you compile code, the variable names, comments, and structure are stripped away to create machine code (ASM).
To decompile PureBasic effectively, you should use disassemblers or low-level decompilers that translate the binary back into Assembly or C. 🛠️ Recommended Tools
Since PureBasic compiles to native code (x86/x64), you need industry-standard reverse engineering tools rather than a PureBasic-specific utility.
Ghidra: A free, open-source suite from the NSA. Its decompiler is excellent at turning machine code back into C-like pseudocode.
IDA Pro / IDA Free: The industry standard for disassembling. It helps you see the logic flow of the PureBasic executable.
x64dbg: A debugger that allows you to step through the code as it runs. This is the best way to see how PureBasic handles memory and variables in real-time.
diStorm: A library often used by PureBasic developers to create their own disassemblers or analyze binary structures. 💡 Better Decompilation Strategies
To get "better" results, you have to look for the "fingerprints" PureBasic leaves behind:
Identify the Libraries: PureBasic uses static libraries for things like OpenWindow() or MessageRequester(). If you see calls to these in the assembly, you can quickly identify what that section of code is doing.
Look for String Constants: Use a tool like Strings (from Sysinternals) or the built-in viewer in Ghidra. PureBasic often stores text strings in a dedicated section of the .exe, which can give you clues about function names or logic.
Understand the Backend: PureBasic 6.0+ introduced a C backend. If the program was compiled using the C backend, using a C decompiler like the one in Ghidra will yield much more readable results than if it were compiled with the older ASM backend.
External Tools: If you just want to see the ASM while you are writing code, use the PBasmUI tool to view and edit the assembly directly in the IDE. ⚠️ Important Limitations
No Original Names: You will not get your original variable names (e.g., MyTotalCount) back. They will look like var_1 or dword_401000.
Optimization: The compiler might rearrange your code for speed, making the decompiled version look very different from your original logic. If you'd like, I can help you with: How to setup Ghidra for PureBasic files Finding specific strings or functions inside a binary
Protecting your own PureBasic code from being easily decompiled
We don’t need a miracle. We need three things: