shellcode-dev SKILL.md skillA
shellcode-dev from hypnguyen1209/offensive-claude is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add hypnguyen1209/offensive-claude/shellcode-dev@git:20260629.9f4a1a5Pins git:20260629.9f4a1a5 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- hypnguyen1209/offensive-claude
- Path
skills/shellcode-dev/SKILL.md- Versions recorded
- 4
- Latest version
- git:20260629.9f4a1a5, committed Jun 29, 2026
- First version recorded
- May 19, 2026
- Size
- 18,565 bytes
- Repository stars
- 410
- License
- MIT
Use when writing position-independent shellcode or a loader — PEB walking, API hashing, null-byte avoidance, encoders, loaders, PE-to-shellcode conversion, cross-platform shellcode.
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
# Shellcode Development ## When to Activate - Writing custom x86/x64 shellcode - Implementing position-independent code (PIC) - Building shellcode loaders for implant delivery - Evading AV/EDR static detection - Converting PE files to shellcode - Cross-platform shellcode development ## Execution Pattern (Allocate-Write-Execute) Avoid direct `PAGE_EXECUTE_READWRITE` — prefer two-step: ```c // 1. Allocate with RW char *dest = VirtualAlloc(NULL, size, MEM_COMMIT|MEM_RESERVE, PAGE_READWRITE); // 2. Write shellcode memcpy(dest, shellcode, size); // 3. Switch to RX (no write permission) VirtualProtect(dest, size, PAGE_EXECUTE_READ, &old); // 4. Execute ((void(*)())dest)(); ``` ## Position-Independent Code (PIC) | Method | Platform | Notes | |--------|----------|-------| | Call/Pop | Windows | Push next addr, pop into register | | FPU state (fstenv) | Windows | Saves instruction pointer | | SEH | Windows | Exception handler stores EIP | | RIP-relative | x64 | `lea rax, [rip+offset]` | | GOT | Linux | Global Offset Table | | VDSO | Linux | Kernel-provided shared object | ## Windows API Resolution (PEB Walk) ```nasm ; x64 PEB walk to find kernel32.dll base find_kernel32: …
Read the whole file at its exact version.
How to install
mdr add hypnguyen1209/offensive-claude/shellcode-dev@sha256:05c14c864991a506The line at the top of this page pins the label git:20260629.9f4a1a5, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_4p26hc3zzmob5kun)
4 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 4 versions of this file, between May 19, 2026 and Jun 29, 2026, about one every 14 days.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20260629.9f4a1a5 latest | 2026-06-29 | 9f4a1a5 | 18,565 B | A | view · diff |
| git:20260528.c57f98d | 2026-05-28 | c57f98d | 18,543 B | A | view · diff |
| git:20260528.6136b32 | 2026-05-28 | 6136b32 | 7,907 B | A | view · diff |
| git:20260519.5ae9faf | 2026-05-19 | 5ae9faf | 7,654 B | A | view |
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (18565 bytes)
- pass: No zero-width or bidi control characters
- pass: No instruction hidden inside an HTML comment
- pass: No link to an exfiltration or paste host
- pass: No credential-shaped string
- pass: No instruction to send local credentials anywhere
- pass: No text hidden with inline styles
- pass: No prompt-injection phrasing
- pass: No curl or wget piped into a shell
- pass: No recursive delete of root, home or parent
- pass: No instruction to read or print local credentials
- pass: No base64 blob over 200 characters
- pass: No link to a raw IP address
- pass: No script tag
Source
hypnguyen1209/offensive-claude · 410 stars · license MIT · pushed 2026-10-22 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_4p26hc3zzmob5kun GET https://markdownregistry.com/api/v1/resolve?ref=hypnguyen1209/offensive-claude/shellcode-dev GET https://markdownregistry.com/api/v1/blob/05c14c864991a506c5e205a9890ffe03a8325da1da9d06f38a8338e37769e6a1
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.