Windows 10/11
64-bit (x64) only
Official CJK Workbench website
Reverse engineering you can check line by line
CJK Workbench 2.9.22 is a Windows app that reads the listings your own disassembler exports, explains the assembly in plain words and keeps your notes in files you can review.
Read exports/add.lst, explain the function and save my notes to notes/add.md.
- Shell
certutil -hashfile add.exe SHA256exit 0 - read_file
exports/add.lsttext read - grep
call exports/add.lst3 matches - write_file
notes/add.mdsaved - edit_file
notes/add.md+6 lines - read_file
notes/add.mdchecked
Waiting for your OK before the next stepRejectAccept
2.9.22
Released 28 Oct 2026
About 34 MB
Portable .exe is about 25 MB
13 languages
No account needed to run
Three
Auto-run, Ask first, Plan only
No telemetry
Chats, folders and keys stay local
What reverse engineering means for a learner
Reverse engineering means studying a finished program or file to understand how it works when the source is not available. Lawful uses include learning, defending against malware, interoperability checks and recovering how your own old program worked. Law and licence terms differ by country and by product, so check them first. This is not legal advice. CJK Workbench 2.9.22 helps with the reading and the notes.
Read a function from your own C build
Seeing how a C function appears in assembly next to its source is the classic first exercise. Compile a small C program of your own and let Shell run your disassembler's export command on a copy of it to save a text listing. The listing is plain text. read_file opens it, and the agent explains each instruction, noting that on 64-bit Windows the first 4 integer arguments travel in rcx, rdx, r8 and r9. write_file saves the explanation to notes/add.md, and in Ask first mode you read the diff and compare it with your source before accepting.
Tool trace
Shell your disassembler's export command on a copy → exit 0
read_file exports/add.lst → text read
write_file notes/add.md → savedUse a Python helper to list strings
A small Python script is a common companion to any study, and the agent can write one for you. Ask for strings.py, which reads a copy of your practice file as bytes and writes every readable string to a text file. write_file saves the script, then Shell runs your Python command on the copy and reports the real exit code. Read the script first. In Ask first, confirm that it only reads bytes from the copy and does not run it before you accept. Run it on 2 copies and search the output with grep.
Tool trace
write_file tools/strings.py → saved
Shell your Python command tools/strings.py copy.bin → exit 0
grep error notes/strings.txt → 3 matchesRead a screenshot of a disassembler window
Sometimes a listing exists only on screen, for example in a tool that cannot export text. ocr reads the text from a screenshot of your own file or practice material, and write_file stores it as a text file so that grep can search it. OCR can misread characters. Open the screenshot beside the text file, compare at least 3 lines, and let edit_file fix each mistake you find, with the diff showing exactly what changed.
Compare several listings with sub-agents
Once you have 3 exported listings from your own build, task can hand each one to its own sub-agent, and each returns a short summary of the functions it found. Start in Plan only, which writes the steps and runs nothing. When the plan looks right, switch mode, and each sub-agent opens its own listing with read_file. One notes file collects them. Check every summary against its listing yourself, because explanations can be wrong.
How it differs from a typical chat assistant
A chat reply is text. CJK Workbench 2.9.22 runs tools in your working folder and shows the real result of each action as a card you can expand.
| Typical chat assistant | CJK Workbench | |
|---|---|---|
| Listings | You paste snippets into the chat window | Reads and searches exports in your working folder |
| Notes | Notes stay inside the conversation | Writes notes files and shows each change as a diff |
| Commands | Suggests commands for you to type | Runs them with Shell and reports the real exit code |
| Review | Gives an answer and leaves checking to you | Ask first shows a diff before a change is saved |
How it works in four steps
- Compare the installer's SHA-256 checksum with the published manifest, then install CJK Workbench on Windows 10 or 11.
- Connect a cloud model, a local model or the built-in model, then press Test to check the endpoint.
- Choose a working folder that holds only your own files, practice binaries and exported listings.
- Pick Ask first or Plan only, describe the task and review every diff before you accept it.
Who it is for
The first audience is self-taught learners looking for reverse engineering for beginners, who need a safe first project such as a small C program they wrote themselves. The agent explains the listing one instruction at a time. Try an 8 line function.
Students on a reverse engineering course at a college often get a CTF as homework, and CJK Workbench keeps their findings in one notes file for each challenge. Use only the course's binaries. Check the contest rules before you begin, because law and licence terms differ by country.
Defenders and analysts use reverse engineering in cyber security to understand malware samples they may lawfully examine, always inside a VM, which is an isolated virtual machine with a clean snapshot and no shared folders. Samples stay inside the VM. CJK Workbench 2.9.22 reads text exports and is never meant for building or changing malware.
Common questions
What is reverse engineering?
Reverse engineering is the study of a finished program or file to learn how it works when the source code is not available. Common lawful uses are learning, security research on software you may examine and recovering how your own old program worked. Law and licence terms differ by country. Check your own country's rules.
Is cjkcode.com the official CJK Workbench website?
Yes, cjkcode.com is the official CJK Workbench website. Download only the original build from the download page and compare its SHA-256 checksum with the published manifest before you run it, because the installer is not code-signed yet. Check the checksum first. Questions go through the Send feedback button inside the app.
Can I analyse any program I find?
No. Analyse only files you own, files you have written permission to examine, open-source software and practice material such as CTF binaries from a contest that allows it. Law and licence terms differ by country and by product, so check them before you begin, because this site is not legal advice.
Does CJK Workbench disassemble programs?
No. It reads the text that your own tools produce, such as disassembly listings, strings output and decompiler output saved to a file, and it explains and organises that text. It does not unpack, patch or run unknown programs. Use your own disassembler for the listing.
Which reverse engineering tools do I need next to it?
A disassembler or decompiler of your own choice comes first, because CJK Workbench does not produce listings itself, and a text editor plus a Python command cover the helper scripts. Both are your choice. Install them inside a VM if you plan to open anything you do not trust.
Can it replace a reverse engineering course?
No. CJK Workbench has no lessons or syllabus of its own, so it works beside a book, a course or a practice contest that you already follow. It reads the listings you export and explains them line by line while it keeps your notes. Pair it with a book.
Can I trust its explanation of the assembly?
No. Explanations of assembly can be wrong, so you confirm each one against the listing and, where lawful, with a test run in a lab. Ask first shows the diff before a notes change is saved. Treat it as a draft.
Open your first listing
Version 2.9.22 is about 34 MB as a setup program, and a portable single .exe of about 25 MB also exists for Windows 10 and 11. Choose a file you own.
Download CJK Workbench for Windows ↗Keep reading
Every page is also available in 20 languages.
What the agent can do with your listings ↗ Choose a cloud, local or built-in model ↗ A step-by-step assembly walkthrough ↗ Download and verify the installer ↗ Answers about scope, privacy and results ↗ What this site and the app store ↗
