pompelmi

<a href="https://www.producthunt.com/products/pompelmi?embed=true&utm_source=badge-pompelmi&utm_medium=badge" target="_blank"><img src="https://api.producthunt.com/widgets/embed-image/v1/featured.svg?post_id=1010722&theme=light&t=1756653468504" alt="pompelmi - free, open-source file scanner | Product Hunt" style="width: 250px; height: 54px;" width="250" height="54" /></a> <a href="https://github.com/pompelmi/pompelmi" target="_blank" rel="noopener noreferrer"> <img src="https://raw.githubusercontent.com/pompelmi/pompelmi/refs/heads/main/assets/logo.svg" alt="pompelmi logo" width="360" /> </a> <a href="https://www.detectionengineering.net/p/det-eng-weekly-issue-124-the-defcon"><img alt="Featured in Detection Engineering Weekly #124" src="https://img.shields.io/badge/featured-Detection%20Engineering%20Weekly-0A84FF?logo=substack"></a> <a href="https://nodeweekly.com/issues/594"><img alt="Featured in Node Weekly #594" src="https://img.shields.io/badge/featured-Node%20Weekly%20%23594-FF6600?logo=node.js"></a> <a href="https://bytes.dev/archives/429"><img alt="Featured in Bytes #429" src="https://img.shields.io/badge/featured-Bytes%20%23429-111111"></a> <a href="https://dev.to/sonotommy/secure-nodejs-file-uploads-in-minutes-with-pompelmi-3jfe"><img alt="Featured on DEV.to" src="https://img.shields.io/badge/featured-DEV.to-0A0A0A?logo=devdotto"></a> <a href="https://github.com/sorrycc/awesome-javascript"><img alt="Mentioned in Awesome JavaScript" src="https://awesome.re/mentioned-badge.svg"></a> <a href="https://github.com/dzharii/awesome-typescript"><img alt="Mentioned in Awesome TypeScript" src="https://awesome.re/mentioned-badge-flat.svg"></a> <h1 align="center">pompelmi</h1> Fast file‑upload malware scanning for Node.js — optional YARA integration, ZIP deep‑inspection, and drop‑in adapters for Express, Koa, and Next.js. Private by design. Typed. Tiny. **Keywords:** file upload security · malware detection · YARA · Node.js middleware · Express · Koa · Next.js · ZIP bomb protection <a href="https://www.npmjs.com/package/pompelmi"><img alt="npm version" src="https://img.shields.io/npm/v/pompelmi?label=version&color=0a7ea4&logo=npm"></a> <a href="https://www.npmjs.com/package/pompelmi"><img alt="npm downloads" src="https://img.shields.io/npm/dm/pompelmi?label=downloads&color=6E9F18&logo=npm"></a> <a href="https://www.npmjs.com/package/pompelmi"><img alt="npm weekly downloads" src="https://img.shields.io/npm/dw/pompelmi?label=weekly&color=blue&logo=npm"></a> <a href="https://www.npmjs.com/package/pompelmi"><img alt="npm total downloads" src="https://img.shields.io/npm/dt/pompelmi?label=total%20downloads&color=success&logo=npm"></a> <img alt="npm bundle size" src="https://img.shields.io/bundlephobia/minzip/pompelmi?label=size&color=success"> <a href="https://snyk.io/test/github/pompelmi/pompelmi"><img alt="Known Vulnerabilities" src="https://snyk.io/test/github/pompelmi/pompelmi/badge.svg"></a> <img alt="node" src="https://img.shields.io/badge/node-%3E%3D18-339933?logo=node.js&logoColor=white"> <img alt="types" src="https://img.shields.io/badge/types-TypeScript-3178C6?logo=typescript&logoColor=white"> <img alt="ESM" src="https://img.shields.io/badge/ESM%2FCJS-compatible-yellow"> <a href="https://github.com/pompelmi/pompelmi/blob/main/LICENSE"><img alt="license" src="https://img.shields.io/npm/l/pompelmi?color=blue"></a> <a href="https://github.com/pompelmi/pompelmi/actions/workflows/ci-release-publish.yml"><img alt="CI Status" src="https://img.shields.io/github/actions/workflow/status/pompelmi/pompelmi/ci-release-publish.yml?branch=main&label=CI&logo=github"></a> <a href="https://codecov.io/gh/pompelmi/pompelmi"><img alt="codecov" src="https://codecov.io/gh/pompelmi/pompelmi/branch/main/graph/badge.svg?flag=core"/></a> <a href="https://securityscorecards.dev/viewer/?uri=github.com/pompelmi/pompelmi"><img alt="OpenSSF Scorecard" src="https://api.securityscorecards.dev/projects/github.com/pompelmi/pompelmi/badge"/></a> <a href="https://bestpractices.coreinfrastructure.org/projects/9999"><img alt="OpenSSF Best Practices" src="https://img.shields.io/badge/OpenSSF-Best%20Practices-green?logo=openbadges"></a> <a href="https://github.com/pompelmi/pompelmi/stargazers"><img alt="GitHub stars" src="https://img.shields.io/github/stars/pompelmi/pompelmi?style=social"></a> <a href="https://github.com/pompelmi/pompelmi/network/members"><img alt="GitHub forks" src="https://img.shields.io/github/forks/pompelmi/pompelmi?style=social"></a> <a href="https://github.com/pompelmi/pompelmi/watchers"><img alt="GitHub watchers" src="https://img.shields.io/github/watchers/pompelmi/pompelmi?style=social"></a> <a href="https://github.com/pompelmi/pompelmi/issues"><img alt="open issues" src="https://img.shields.io/github/issues/pompelmi/pompelmi?color=orange"></a> <img alt="PRs welcome" src="https://img.shields.io/badge/PRs-welcome-brightgreen.svg"> <a href="https://github.com/pompelmi/pompelmi/commits/main"><img alt="last commit" src="https://img.shields.io/github/last-commit/pompelmi/pompelmi?color=blue"></a> <a href="https://github.com/pompelmi/pompelmi/graphs/contributors"><img alt="contributors" src="https://img.shields.io/github/contributors/pompelmi/pompelmi?color=purple"></a> <a href="https://pompelmi.github.io/pompelmi/">📚 Documentation</a> • <a href="#installation">💾 Install</a> • <a href="#quick-start">⚡ Quick Start</a> • <a href="#adapters">🧩 Adapters</a> • <a href="#yara-getting-started">🧬 YARA</a> • <a href="#github-action">🤖 CI/CD</a> • <a href="#faq">❓ FAQ</a> Coverage badge reflects core library (<code>src/**</code>); adapters are measured separately.  --- <div align="center"> ### 🎯 Why Choose pompelmi? </div> | 🔒 Privacy First | ⚡ Lightning Fast | 🎨 Developer Friendly | | --- | --- | --- | | All scanning happens in-process. No cloud calls, no data leaks. Your files never leave your infrastructure. | In-process scanning with zero network latency. Configurable concurrency for high-throughput scenarios. | TypeScript-first, zero-config defaults, drop-in middleware. Get started in under 5 minutes. | --- ## Table of Contents - [Overview](#overview) - [Highlights](#highlights) - [Why pompelmi](#why-pompelmi) - [How it compares](#how-it-compares) - [What Developers Say](#what-developers-say) - [What Makes pompelmi Special](#what-makes-pompelmi-special) - [Use Cases](#use-cases) - [Installation](#installation) - [Quick Start](#quick-start) - [Minimal Node usage](#minimal-node-usage) - [Express](#express) - [Koa](#koa) - [Next.js (App Router)](#nextjs-app-router) - [Configuration](#configuration) - [Security Notes](#security-notes) - [Testing & Development](#testing--development) - [FAQ](#faq) - [Contributing](#contributing) - [License](#license) --- ## 🚀 Overview **pompelmi** scans untrusted file uploads **before** they hit disk. A tiny, TypeScript-first toolkit for Node.js with composable scanners, deep ZIP inspection, and optional signature engines. ### 🎯 Key Features **🔒 Private by design** — no outbound calls; bytes never leave your process **🧩 Composable scanners** — mix heuristics + signatures; set `stopOn` and timeouts **📦 ZIP hardening** — traversal/bomb guards, polyglot & macro hints **🔌 Drop-in adapters** — Express, Koa, Fastify, Next.js **📘 Typed & tiny** — modern TS, minimal surface, tree-shakeable **⚡ Zero dependencies** — core library has minimal deps, fast installation ## ✨ Highlights **🛡️ Block risky uploads early** — classify uploads as _clean_, _suspicious_, or _malicious_ and stop them at the edge. **✅ Real guards** — extension allow‑list, server‑side MIME sniff (magic bytes), per‑file size caps, and **deep ZIP** traversal with anti‑bomb limits. **🔍 Built‑in scanners** — drop‑in **CommonHeuristicsScanner** (PDF risky actions, Office macros, PE header) and **Zip‑bomb Guard**; add your own or YARA via a tiny `{ scan(bytes) }` contract. **⚙️ Compose scanning** — run multiple scanners in parallel or sequentially with timeouts and short‑circuiting via `composeScanners()`. **☁️ Zero cloud** — scans run in‑process. Keep bytes private. Perfect for GDPR/HIPAA compliance. **👨‍💻 DX first** — TypeScript types, ESM/CJS builds, tiny API, adapters for popular web frameworks. > **SEO Keywords:** file upload security, malware detection, virus scanner, Node.js security, Express middleware, YARA integration, ZIP bomb protection, file validation, upload sanitization, threat detection, security scanner, antivirus Node.js, file scanning library, TypeScript security, Next.js security, Koa middleware, server-side validation, file integrity check, malware prevention, secure file upload ## 🧠 Why pompelmi? - **On‑device, private scanning** – no outbound calls, no data sharing. - **Blocks early** – runs _before_ you write to disk or persist anything. - **Fits your stack** – drop‑in adapters for Express, Koa, Next.js (Fastify plugin in alpha). - **Defense‑in‑depth** – ZIP traversal limits, ratio caps, server‑side MIME sniffing, size caps. - **Pluggable detection** – bring your own engine (e.g., YARA) via a tiny `{ scan(bytes) }` contract. ### Who is it for? - Teams who can’t send uploads to third‑party AV APIs. - Apps that need predictable, low‑latency decisions inline. - Developers who want simple, typed building blocks instead of a daemon. ## 🔍 How it compares | Capability | pompelmi | ClamAV / node‑clam | Cloud AV APIs | | --- | --- | --- | --- | | Runs fully in‑process | ✅ | ❌ (separate daemon) | ❌ (network calls) | | Bytes stay private | ✅ | ✅ | ❌ | | Deep ZIP limits & MIME sniff | ✅ | ✅ (archive scan) | ❓ varies | | YARA integration | ✅ optional | ❌* | ❓ varies | | Framework adapters | ✅ Express/Koa/Next.js | ❌ | ❌ | | Works in CI on artifacts | ✅ | ✅ | ❓ varies | | Licensing | MIT | GPL (engine) | Proprietary | \* You can run YARA alongside ClamAV, but it’s not built‑in. --- ## 💬 What Developers Say > "pompelmi made it incredibly easy to add malware scanning to our Express API. The TypeScript support is fantastic!" > — Developer using pompelmi in production > "Finally, a file scanning solution that doesn't require sending our users' data to third parties. Perfect for GDPR compliance." > — Security Engineer at a healthcare startup > "The YARA integration is seamless. We went from prototype to production in less than a week." > — DevSecOps Engineer _Want to share your experience? [Open a discussion](https://github.com/pompelmi/pompelmi/discussions)!_ --- ## 🌟 What Makes pompelmi Special? ### 🎯 Developer Experience Built with developers in mind from day one. Simple API, comprehensive TypeScript types, and excellent documentation mean you can integrate secure file scanning in minutes, not days. Hot module replacement support and detailed error messages make debugging a breeze. ### 🚀 Performance First Optimized for high-throughput scenarios with configurable concurrency, streaming support, and minimal memory overhead. Process thousands of files without breaking a sweat. Scans run in-process with no IPC overhead. ### 🔐 Security Without Compromise Multi-layered defense including MIME type verification (magic bytes), extension validation, size limits, ZIP bomb protection, and optional YARA integration. Each layer is configurable to match your threat model. ### 🌍 Privacy Guaranteed Your data never leaves your infrastructure. No telemetry, no cloud dependencies, no third-party API calls. Perfect for regulated industries (healthcare, finance, government) and privacy-conscious applications. --- ## 💡 Use Cases pompelmi is trusted across diverse industries and use cases: ### 🏥 Healthcare (HIPAA Compliance) Scan patient document uploads without sending PHI to third-party services. Keep medical records and imaging files secure on your infrastructure. ### 🏦 Financial Services (PCI DSS) Validate customer document uploads (ID verification, tax forms) without exposing sensitive financial data to external APIs. ### 🎓 Education Platforms Protect learning management systems from malicious file uploads while maintaining student privacy. ### 📱 SaaS Applications Add secure file upload capabilities to your multi-tenant platform with per-tenant policy customization. ### 🏢 Enterprise Document Management Scan files at ingestion time for corporate file sharing platforms, wikis, and collaboration tools. ### 🎨 Media & Creative Platforms Validate user-generated content uploads (images, videos, documents) before processing and storage. --- ## 🔧 Installation <table> <tr> <td>npm</td> <td><code>npm install pompelmi</code></td> </tr> <tr> <td>pnpm</td> <td><code>pnpm add pompelmi</code></td> </tr> <tr> <td>yarn</td> <td><code>yarn add pompelmi</code></td> </tr> <tr> <td>bun</td> <td><code>bun add pompelmi</code></td> </tr> </table> ### 📦 Optional Framework Adapters ```bash # Express npm i @pompelmi/express-middleware # Koa npm i @pompelmi/koa-middleware # Next.js npm i @pompelmi/next-upload # Fastify (alpha) npm i @pompelmi/fastify-plugin ``` > **Note:** Core library works standalone. Install adapters only if using specific frameworks. > Optional dev deps used in the examples: > > ```bash > npm i -D tsx express multer @koa/router @koa/multer koa next > ``` --- ## ⚡ Quick‑start **At a glance (policy + scanners)** ```ts // Compose built‑in scanners (no EICAR). Optionally add your own/YARA. import { CommonHeuristicsScanner, createZipBombGuard, composeScanners } from 'pompelmi'; export const policy = { includeExtensions: ['zip','png','jpg','jpeg','pdf'], allowedMimeTypes: ['application/zip','image/png','image/jpeg','application/pdf','text/plain'], maxFileSizeBytes: 20 * 1024 * 1024, timeoutMs: 5000, concurrency: 4, failClosed: true, onScanEvent: (ev: unknown) => console.log('[scan]', ev) }; export const scanner = composeScanners( [ ['zipGuard', createZipBombGuard({ maxEntries: 512, maxTotalUncompressedBytes: 100 * 1024 * 1024, maxCompressionRatio: 12 })], ['heuristics', CommonHeuristicsScanner], // ['yara', YourYaraScanner], ], { parallel: false, stopOn: 'suspicious', timeoutMsPerScanner: 1500, tagSourceName: true } ); ``` ### Minimal Node usage ```ts import { scanFile } from 'pompelmi'; const res = await scanFile('path/to/file.zip'); // or any file console.log(res.verdict); // "clean" | "suspicious" | "malicious" ``` > See `examples/scan-one-file.ts` for a runnable script: > > ```bash > pnpm tsx examples/scan-one-file.ts ./path/to/file > ``` ### Express ```ts import express from 'express'; import multer from 'multer'; import { createUploadGuard } from '@pompelmi/express-middleware'; import { policy, scanner } from './security'; // the snippet above const app = express(); const upload = multer({ storage: multer.memoryStorage(), limits: { fileSize: policy.maxFileSizeBytes } }); app.post('/upload', upload.any(), createUploadGuard({ ...policy, scanner }), (req, res) => { res.json({ ok: true, scan: (req as any).pompelmi ?? null }); }); app.listen(3000, () => console.log('http://localhost:3000')); ``` ### Koa ```ts import Koa from 'koa'; import Router from '@koa/router'; import multer from '@koa/multer'; import { createKoaUploadGuard } from '@pompelmi/koa-middleware'; import { policy, scanner } from './security'; const app = new Koa(); const router = new Router(); const upload = multer({ storage: multer.memoryStorage(), limits: { fileSize: policy.maxFileSizeBytes } }); router.post('/upload', upload.any(), createKoaUploadGuard({ ...policy, scanner }), (ctx) => { ctx.body = { ok: true, scan: (ctx as any).pompelmi ?? null }; }); app.use(router.routes()).use(router.allowedMethods()); app.listen(3003, () => console.log('http://localhost:3003')); ``` ### Next.js (App Router) ```ts // app/api/upload/route.ts import { createNextUploadHandler } from '@pompelmi/next-upload'; import { policy, scanner } from '@/lib/security'; export const runtime = 'nodejs'; export const dynamic = 'force-dynamic'; export const POST = createNextUploadHandler({ ...policy, scanner }); ``` --- ## 🤖 GitHub Action Run **pompelmi** in CI to scan repository files or built artifacts. **Minimal usage** ```yaml name: Security scan (pompelmi) on: [push, pull_request] jobs: scan: runs-on: ubuntu-latest steps: - uses: actions/checkout@v4 - name: Scan repository with pompelmi uses: pompelmi/pompelmi/.github/actions/pompelmi-scan@v1 with: path: . deep_zip: true fail_on_detect: true ``` **Scan a single artifact** ```yaml - uses: pompelmi/pompelmi/.github/actions/pompelmi-scan@v1 with: artifact: build.zip deep_zip: true fail_on_detect: true ``` **Inputs** | Input | Default | Description | | --- | --- | --- | | `path` | `.` | Directory to scan. | | `artifact` | `""` | Single file/archive to scan. | | `yara_rules` | `""` | Glob path to YARA rules (e.g. `rules/*.yar`). | | `deep_zip` | `true` | Enable deep nested-archive inspection. | | `max_depth` | `3` | Max nested-archive depth. | | `fail_on_detect` | `true` | Fail the job if detections occur. | > The Action lives in this repo at `.github/actions/pompelmi-scan`. When published to the Marketplace, consumers can copy the snippets above as-is. --- ## 🧩 Adapters Use the adapter that matches your web framework. All adapters share the same policy options and scanning contract. <img src="https://img.shields.io/badge/Express-✓-000000?style=flat-square&logo=express" alt="Express"> <img src="https://img.shields.io/badge/Koa-✓-33333D?style=flat-square&logo=koa" alt="Koa"> <img src="https://img.shields.io/badge/Next.js-✓-000000?style=flat-square&logo=next.js" alt="Next.js"> <img src="https://img.shields.io/badge/Fastify-alpha-000000?style=flat-square&logo=fastify" alt="Fastify"> <img src="https://img.shields.io/badge/NestJS-planned-E0234E?style=flat-square&logo=nestjs" alt="NestJS"> <img src="https://img.shields.io/badge/Remix-planned-000000?style=flat-square&logo=remix" alt="Remix"> <img src="https://img.shields.io/badge/hapi-planned-F26D00?style=flat-square" alt="hapi"> <img src="https://img.shields.io/badge/SvelteKit-planned-FF3E00?style=flat-square&logo=svelte" alt="SvelteKit"> | Framework | Package | Status | | --- | --- | --- | | Express | `@pompelmi/express-middleware` | ✅ alpha | | Koa | `@pompelmi/koa-middleware` | ✅ alpha | | Next.js (App Router) | `@pompelmi/next-upload` | ✅ alpha | | Fastify | `@pompelmi/fastify-plugin` | 🚧 alpha | | NestJS | nestjs | 📋 planned | | Remix | remix | 📋 planned | | hapi | hapi plugin | 📋 planned | | SvelteKit | sveltekit | 📋 planned | --- ## 🗺️ Diagrams ### Upload scanning flow ```mermaid flowchart TD A["Client uploads file(s)"] --> B["Web App Route"] B --> C{"Pre-filters (ext, size, MIME)"} C -- fail --> X["HTTP 4xx"] C -- pass --> D{"Is ZIP?"} D -- yes --> E["Iterate entries (limits & scan)"] E --> F{"Verdict?"} D -- no --> F{"Scan bytes"} F -- malicious/suspicious --> Y["HTTP 422 blocked"] F -- clean --> Z["HTTP 200 ok + results"] ``` <details> <summary>Mermaid source</summary> ```mermaid flowchart TD A["Client uploads file(s)"] --> B["Web App Route"] B --> C{"Pre-filters (ext, size, MIME)"} C -- fail --> X["HTTP 4xx"] C -- pass --> D{"Is ZIP?"} D -- yes --> E["Iterate entries (limits & scan)"] E --> F{"Verdict?"} D -- no --> F{"Scan bytes"} F -- malicious/suspicious --> Y["HTTP 422 blocked"] F -- clean --> Z["HTTP 200 ok + results"] ``` </details> ### Sequence (App ↔ pompelmi ↔ YARA) ```mermaid sequenceDiagram participant U as User participant A as App Route (/upload) participant P as pompelmi (adapter) participant Y as YARA engine U->>A: POST multipart/form-data A->>P: guard(files, policies) P->>P: MIME sniff + size + ext checks alt ZIP archive P->>P: unpack entries with limits end P->>Y: scan(bytes) Y-->>P: matches[] P-->>A: verdict (clean/suspicious/malicious) A-->>U: 200 or 4xx/422 with reason ``` <details> <summary>Mermaid source</summary> ```mermaid sequenceDiagram participant U as User participant A as App Route (/upload) participant P as pompelmi (adapter) participant Y as YARA engine U->>A: POST multipart/form-data A->>P: guard(files, policies) P->>P: MIME sniff + size + ext checks alt ZIP archive P->>P: unpack entries with limits end P->>Y: scan(bytes) Y-->>P: matches[] P-->>A: verdict (clean/suspicious/malicious) A-->>U: 200 or 4xx/422 with reason ``` </details> ### Components (monorepo) ```mermaid flowchart LR subgraph Repo core["pompelmi (core)"] express["@pompelmi/express-middleware"] koa["@pompelmi/koa-middleware"] next["@pompelmi/next-upload"] fastify(("fastify-plugin · planned")) nest(("nestjs · planned")) remix(("remix · planned")) hapi(("hapi-plugin · planned")) svelte(("sveltekit · planned")) end core --> express core --> koa core --> next core -.-> fastify core -.-> nest core -.-> remix core -.-> hapi core -.-> svelte ``` <details> <summary>Mermaid source</summary> ```mermaid flowchart LR subgraph Repo core["pompelmi (core)"] express["@pompelmi/express-middleware"] koa["@pompelmi/koa-middleware"] next["@pompelmi/next-upload"] fastify(("fastify-plugin · planned")) nest(("nestjs · planned")) remix(("remix · planned")) hapi(("hapi-plugin · planned")) svelte(("sveltekit · planned")) end core --> express core --> koa core --> next core -.-> fastify core -.-> nest core -.-> remix core -.-> hapi core -.-> svelte ``` </details> --- ## ⚙️ Configuration All adapters accept a common set of options: | Option | Type (TS) | Purpose | | --- | --- | --- | | `scanner` | `{ scan(bytes: Uint8Array): Promise<Match[]> }` | Your scanning engine. Return `[]` when clean; non‑empty to flag. | | `includeExtensions` | `string[]` | Allow‑list of file extensions. Evaluated case‑insensitively. | | `allowedMimeTypes` | `string[]` | Allow‑list of MIME types after magic‑byte sniffing. | | `maxFileSizeBytes` | `number` | Per‑file size cap. Oversize files are rejected early. | | `timeoutMs` | `number` | Per‑file scan timeout; guards against stuck scanners. | | `concurrency` | `number` | How many files to scan in parallel. | | `failClosed` | `boolean` | If `true`, errors/timeouts block the upload. | | `onScanEvent` | `(event: unknown) => void` | Optional telemetry hook for logging/metrics. | **Common recipes** Allow only images up to 5 MB: ```ts includeExtensions: ['png','jpg','jpeg','webp'], allowedMimeTypes: ['image/png','image/jpeg','image/webp'], maxFileSizeBytes: 5 * 1024 * 1024, failClosed: true, ``` --- ## ✅ Production checklist - [ ] **Limit file size** aggressively (`maxFileSizeBytes`). - [ ] **Restrict extensions & MIME** to what your app truly needs. - [ ] **Set `failClosed: true` in production** to block on timeouts/errors. - [ ] **Handle ZIPs carefully** (enable deep ZIP, keep nesting low, cap entry sizes). - [ ] **Compose scanners** with `composeScanners()` and enable `stopOn` to fail fast on early detections. - [ ] **Log scan events** (`onScanEvent`) and monitor for spikes. - [ ] **Run scans in a separate process/container** for defense‑in‑depth when possible. - [ ] **Sanitize file names and paths** if you persist uploads. - [ ] **Prefer memory storage + post‑processing**; avoid writing untrusted bytes before policy passes. - [ ] **Add CI scanning** with the GitHub Action to catch bad files in repos/artifacts. --- ## 🧬 YARA Getting Started YARA lets you detect suspicious or malicious content using pattern‑matching rules. **pompelmi** treats YARA matches as signals that you can map to your own verdicts (e.g., mark high‑confidence rules as `malicious`, heuristics as `suspicious`). > **Status:** Optional. You can run without YARA. If you adopt it, keep your rules small, time‑bound, and tuned to your threat model. ### Starter rules Below are three example rules you can adapt: `rules/starter/eicar.yar` ```yar rule EICAR_Test_File { meta: description = "EICAR antivirus test string (safe)" reference = "https://www.eicar.org" confidence = "high" verdict = "malicious" strings: $eicar = "X5O!P%@AP[4\\PZX54(P^)7CC)7}$EICAR-STANDARD-ANTIVIRUS-TEST-FILE!$H+H*" condition: $eicar } ``` `rules/starter/pdf_js.yar` ```yar rule PDF_JavaScript_Embedded { meta: description = "PDF contains embedded JavaScript (heuristic)" confidence = "medium" verdict = "suspicious" strings: $magic = { 25 50 44 46 } // "%PDF" $js1 = "/JavaScript" ascii $js2 = "/JS" ascii $open = "/OpenAction" ascii $aa = "/AA" ascii condition: uint32(0) == 0x25504446 and ( $js1 or $js2 ) and ( $open or $aa ) } ``` `rules/starter/office_macros.yar` ```yar rule Office_Macro_Suspicious_Words { meta: description = "Heuristic: suspicious VBA macro keywords" confidence = "medium" verdict = "suspicious" strings: $s1 = /Auto(Open|Close)/ nocase $s2 = "Document_Open" nocase ascii $s3 = "CreateObject(" nocase ascii $s4 = "WScript.Shell" nocase ascii $s5 = "Shell(" nocase ascii $s6 = "Sub Workbook_Open()" nocase ascii condition: 2 of ($s*) } ``` > These are **examples**. Expect some false positives; tune to your app. ### Minimal integration (adapter contract) If you use a YARA binding (e.g., `@automattic/yara`), wrap it behind the `scanner` contract: ```ts // Example YARA scanner adapter (pseudo‑code) import * as Y from '@automattic/yara'; // Compile your rules from disk at boot (recommended) // const sources = await fs.readFile('rules/starter/*.yar', 'utf8'); // const compiled = await Y.compile(sources); export const YourYaraScanner = { async scan(bytes: Uint8Array) { // const matches = await compiled.scan(bytes, { timeout: 1500 }); const matches = []; // plug your engine here // Map to the structure your app expects; return [] when clean. return matches.map((m: any) => ({ rule: m.rule, meta: m.meta ?? {}, tags: m.tags ?? [], })); } }; ``` Then include it in your composed scanner: ```ts import { composeScanners, CommonHeuristicsScanner } from 'pompelmi'; // import { YourYaraScanner } from './yara-scanner'; export const scanner = composeScanners( [ ['heuristics', CommonHeuristicsScanner], // ['yara', YourYaraScanner], ], { parallel: false, stopOn: 'suspicious', timeoutMsPerScanner: 1500, tagSourceName: true } ); ``` ### Policy suggestion (mapping matches → verdict) - **malicious**: high‑confidence rules (e.g., `EICAR_Test_File`) - **suspicious**: heuristic rules (e.g., PDF JavaScript, macro keywords) - **clean**: no matches Combine YARA with MIME sniffing, ZIP safety limits, and strict size/time caps. ## 🧪 Quick test (no EICAR) Use the examples above, then send a **minimal PDF** that contains risky tokens (this triggers the built‑in heuristics). **1) Create a tiny PDF with risky actions** Linux: ```bash printf '%%PDF-1.7\n1 0 obj\n<< /OpenAction 1 0 R /AA << /JavaScript (alert(1)) >> >>\nendobj\n%%EOF\n' > risky.pdf ``` macOS: ```bash printf '%%PDF-1.7\n1 0 obj\n<< /OpenAction 1 0 R /AA << /JavaScript (alert(1)) >> >>\nendobj\n%%EOF\n' > risky.pdf ``` **2) Send it to your endpoint** Express (default from the Quick‑start): ```bash curl -F "file=@risky.pdf;type=application/pdf" http://localhost:3000/upload -i ``` You should see an HTTP **422 Unprocessable Entity** (blocked by policy). Clean files return **200 OK**. Pre‑filter failures (size/ext/MIME) should return a **4xx**. Adapt these conventions to your app as needed. --- ## 🔒 Security notes - The library **reads** bytes; it never executes files. - YARA detections depend on the **rules you provide**; expect some false positives/negatives. - ZIP scanning applies limits (entries, per‑entry size, total uncompressed, nesting) to reduce archive‑bomb risk. - Prefer running scans in a **dedicated process/container** for defense‑in‑depth. --- [...] ## 🔔 Releases & security - **Changelog / releases:** see [GitHub Releases](https://github.com/pompelmi/pompelmi/releases). - **Security disclosures:** please use [GitHub Security Advisories](https://github.com/pompelmi/pompelmi/security/advisories). We’ll coordinate a fix before public disclosure. - **Production users:** open a [Discussion](https://github.com/pompelmi/pompelmi/discussions) to share requirements or request adapters. ## ⭐ Star history [![Star History Chart](https://api.star-history.com/svg?repos=pompelmi/pompelmi&type=Date)](https://star-history.com/#pompelmi/pompelmi&Date) --- ## 🏆 Community & Recognition pompelmi has been featured in leading developer publications and is trusted by teams worldwide for secure file upload handling. <img src="https://img.shields.io/badge/Featured%20in-Detection%20Engineering%20Weekly-0A84FF?style=for-the-badge&logo=substack" alt="Detection Engineering"> <img src="https://img.shields.io/badge/Featured%20in-Node%20Weekly-FF6600?style=for-the-badge&logo=node.js" alt="Node Weekly"> <img src="https://img.shields.io/badge/Featured%20in-Bytes-111111?style=for-the-badge" alt="Bytes"> ### 🤝 Join the Community - 💬 [GitHub Discussions](https://github.com/pompelmi/pompelmi/discussions) — Ask questions, share ideas - 🐛 [Issue Tracker](https://github.com/pompelmi/pompelmi/issues) — Report bugs, request features - 📖 [Documentation](https://pompelmi.github.io/pompelmi/) — Comprehensive guides and API reference - 🔒 [Security](https://github.com/pompelmi/pompelmi/security) — Report security vulnerabilities privately --- ## 💬 FAQ **Do I need YARA?** No. `scanner` is pluggable. The examples use a minimal scanner for clarity; you can call out to a YARA engine or any other detector you prefer. **Where do the results live?** In the examples, the guard attaches scan data to the request context (e.g. `req.pompelmi` in Express, `ctx.pompelmi` in Koa). In Next.js, include the results in your JSON response as you see fit. **Why 422 for blocked files?** Using **422** to signal a policy violation keeps it distinct from transport errors; it’s a common pattern. Use the codes that best match your API guidelines. **Are ZIP bombs handled?** Archives are traversed with limits to reduce archive‑bomb risk. Keep your size limits conservative and prefer `failClosed: true` in production. --- ## 🧪 Tests & Coverage Run tests locally with coverage: ```bash pnpm vitest run --coverage --passWithNoTests ``` The badge tracks the **core library** (`src/**`). Adapters and engines are reported separately for now and will be folded into global coverage as their suites grow. If you integrate Codecov in CI, upload `coverage/lcov.info` and you can use this Codecov badge: ```md [![codecov](https://codecov.io/gh/pompelmi/pompelmi/branch/main/graph/badge.svg?flag=core)](https://codecov.io/gh/pompelmi/pompelmi) ``` ## 🤝 Contributing PRs and issues welcome! Start with: ```bash pnpm -r build pnpm -r lint ``` See [CONTRIBUTING.md](./CONTRIBUTING.md) for detailed guidelines. ### 🎖️ Contributors Thanks to all the amazing contributors who have helped make pompelmi better!  --- ## 🎓 Learning Resources ### 📚 Documentation - [Official Docs](https://pompelmi.github.io/pompelmi/) — Complete API reference and guides - [Examples](./examples/) — Real-world integration examples - [Security Guide](./SECURITY.md) — Security best practices and disclosure policy ### 🎥 Tutorials & Articles - **File Upload Security in Node.js** — Best practices guide (coming soon) - **Integrating YARA with pompelmi** — Advanced detection setup (coming soon) - **Zero-Trust File Uploads** — Architecture patterns (coming soon) ### 🛠️ Tools & Integrations - [GitHub Action](https://github.com/pompelmi/pompelmi/tree/main/.github/actions/pompelmi-scan) — CI/CD scanning - [Docker Images](https://hub.docker.com/r/pompelmi/pompelmi) — Containerized scanning (coming soon) - [Cloud Functions](https://github.com/pompelmi/cloud-functions) — Serverless examples (coming soon) --- ## 📊 Project Stats <img src="https://repobeats.axiom.co/api/embed/YOUR_EMBED_ID.svg" alt="Repobeats analytics" /> --- ## 🙏 Acknowledgments pompelmi stands on the shoulders of giants. Special thanks to: - The YARA project for powerful pattern matching - The Node.js community for excellent tooling - All our contributors and users --- ## 📞 Support Need help? We're here for you! - 📖 [Documentation](https://pompelmi.github.io/pompelmi/) - 💬 [GitHub Discussions](https://github.com/pompelmi/pompelmi/discussions) - 🐛 [Issue Tracker](https://github.com/pompelmi/pompelmi/issues) - 🔒 [Security](https://github.com/pompelmi/pompelmi/security) (for vulnerabilities) For commercial support and consulting, contact the maintainers. --- <a href="#pompelmi">↑ Back to top</a> ## 📜 License [MIT](./LICENSE) © 2025‑present pompelmi contributors