dsl-vm-reverse

dsl-vm-reverse is a skill for Claude Code, Codex from SeaOf0/dsh-redteam-model. It costs 63 tokens per session (3,826 once invoked), scanned A, a copy of dsl-vm-reverse, MIT.

A workflow for reverse engineering JavaScript programs that contain their own small programming language or virtual machine.

In plain words
What is it for?
Use it to identify custom interpreters, recover instruction meanings, capture their runtime state, and reconstruct how the program executes.
Why use it?
These programs hide their real logic behind opcode dispatchers, compressed code, and custom execution states, making ordinary JavaScript reading difficult.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it to identify custom interpreters, recover instruction meanings, capture their runtime state, and reconstruct how the program executes.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/seaof0/dsh-redteam-model/dsl-vm-reverse
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add SeaOf0/dsh-redteam-model --skill dsl-vm-reverse
Clone the repo
git clone --depth 1 https://github.com/SeaOf0/dsh-redteam-model

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for dsl-vm-reverse

README.md
[![agentmods](https://agentmods.dev/badge/skills/seaof0/dsh-redteam-model/dsl-vm-reverse/github.svg)](https://agentmods.dev/skills/seaof0/dsh-redteam-model/dsl-vm-reverse)
Your own site
<a href="https://agentmods.dev/skills/seaof0/dsh-redteam-model/dsl-vm-reverse"><img src="https://agentmods.dev/badge/skills/seaof0/dsh-redteam-model/dsl-vm-reverse/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for dsl-vm-reverse

Your own site · 80×15
<a href="https://agentmods.dev/skills/seaof0/dsh-redteam-model/dsl-vm-reverse"><img src="https://agentmods.dev/badge/skills/seaof0/dsh-redteam-model/dsl-vm-reverse.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 63 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,826 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin 94% copy Near-identical to another mod in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00063 $0.03826
Opus 5 $0.00032 $0.01913
Sonnet 5 $0.00013 $0.00765
Haiku 4.5 $0.00006 $0.00383

Measured 9d ago against content hash 57d1d92f42ea, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

dsl-vm-reverse scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 9d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

This is a copy

94% identical to dsl-vm-reverse — 6 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

modes/binary-analysis/refs/methodology/reverse-engineering/dsl-vm-reverse/SKILL.md · 375 lines

How it starts

The opening of the file, as written. The whole thing — 375 lines — stays where its author put it; the contents beside it link to each section on GitHub.

🔄 DSL 自定义虚拟机逆向(DSL VM Reverse Engineering)

用于逆向基于 JavaScript 实现的自定义 WASM 虚拟机/风控引擎


目录


1. 适用范围

当目标文件符合以下 任意特征 时使用本 skill:

# 特征 说明
1 IIFE 开头 + 大量单字母变量名 !function(){var U=void 0,y=parseInt,E0=Function,...}
2 包含 DG() 或类似函数含 switch-case 循环 解释器主循环,d[7]&31 解码 opcode
3 大文件(500KB+)但零字节占比 < 1% 非标准 WASM,纯 JS
4 包含 C[number] 常量表引用 C[9][xxx] 函数表/字符串表
5 单行压缩代码 583KB 单行,混淆变量名

排除规则

条件 非本 skill 转至
文件以 \x00asm 开头 标准 WASM 二进制 reverse-engineering/languages.md
文件以 Uint8Array([0,97,115,109]) 含 WASM 魔术字 WASM 嵌入式 提取 .wasm 后转 IDA/Ghidra
标准 Webpack 打包(function(e,t,n){...} 普通 JS js-reverse/
零字节占比 > 20% WASM 二进制 reverse-engineering/languages.md

2. DSL VM 识别特征

代码特征

// 特征 1: IIFE 入口,单字母变量映射数字常量
!function(){
    var U=void 0, y=parseInt, E0=Function, AN=Uint8Array;
    var E=15, l=10, m=12, x=16, S=13, $=11;
    // 数字常量映射为变量名,替代原始数字
    ...
}

// 特征 2: 解释器主循环 DG()
function DG(C, d, ...) {
    var d = [];  // 数组模拟 WASM stack/locals
    for (d[7] = x; d[7] !== U;) {
        var aE = d[7] & 31;         // 低 5 位 = opcode
        var O = d[7] >> 5 & 31;      // 高 5 位 = sub-operation
        switch (aE) {
            case 0: /* ... */ d[7] = 612; break;
            case 1: /* ... */
            // ... N 个 case
        }
    }
}

// 特征 3: 常量表 C[9] 存储函数索引和字符串
// C[9][0] = ["pc"]      → 函数参数描述
// C[9][667] = "string"  → 字符串常量
// C[9][x] = number      → 函数索引

// 特征 4: W(C[index], null, ...) 调用模式
// W = Function.prototype.call.bind(call)
// 所有内置函数通过 C[index] 索引调用

// 特征 5: 指令编码格式
// d[7] = opcode(bit 0-4) | subop(bit 5-9) | operand(bit 10+)

Opcode 编码格式

每条指令编码为 32 位整数:

bit 0-4:   opcode (0-N)
bit 5-9:   sub-operation (0-31)
bit 10-31: operand/立即数

解码:
  aE = d[7] & 31        → opcode
  O  = d[7] >> 5 & 31   → sub-operation
  d[other] = d[7] >> 10  → operand

Read the full file on GitHub · 375 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 9d ago First seen · 375 lines · 63 tokens per session scan A 57d1d92f42ea

Subscribe to this mod's changes

dsl-vm-reverse is a skill published in the GitHub repository SeaOf0/dsh-redteam-model (325 stars, last pushed 4d ago), licensed MIT. It adds 63 tokens to every session and 3,826 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. It is 94% identical to dsl-vm-reverse, differing in 6 lines, and is treated as a copy.