--- title: "🛠️ European refrigeration systems hacked and forced to defrost? Coldframe single-file simulates Danfoss controller to lure attackers | Open Source Daily Pick" description: "In 2026, hackers breached European supermarket freezer systems forcing defrost, turning cold chain breach risks from theory into reality; today we introduce Coldframe, a single-file, zero-dependency Python honeypot precisely simulating the web fingerprints of real Danfoss and Dixell controllers, plus LearnHarness, a 9.2k-star AI learning companion desktop app that uses knowledge graphs to solve the pain point of reading docs but not grasping core concepts, and I will tell you why it is not like ordinary chatbots." canonical_url: "https://blog.markkulab.net/en/open-source-weekly/open-source-weekly-2026-11-08" author: "Mark Ku" author_url: "https://blog.markkulab.net/en/author/mark-ku" site: "Mark Ku's Tech Notes" date_published: "2026-11-08T02:00:00.000Z" category: "Open Source Daily Digest" tags: ["open-source", "podcast", "開源工具", "開源", "Coldframe", "LearnHarness", "蜜罐", "工業物聯網", "AI學習", "知識圖譜", "資安"] language: "en" license: "CC BY 4.0" license_url: "https://creativecommons.org/licenses/by/4.0/" attribution: "when reusing or quoting, credit the author and link back to the original" --- # 🛠️ European refrigeration systems hacked and forced to defrost? Coldframe single-file simulates Danfoss controller to lure attackers | Open Source Daily Pick ## Opening In 2026, hackers breached European supermarket refrigeration systems and forced defrost cycles, turning cold-chain rupture risk from theory into live fire. Today we're covering Coldframe, a single-file, zero-dependency honeypot that precisely mimics the web fingerprints of real Danfoss and Dixell controllers, and LearnHarness, a 9.2k-star AI learning companion desktop app that uses knowledge graphs to solve the "read the docs but still don't grasp the core concepts" problem. I'll explain why it's not just another chatbot. ## Today's Open Source Picks ### 1. Coldframe: Single-File Honeypot Built for Real ICS Intrusions - **What it is**: Built in response to the 2026 European refrigeration hack where attackers forced defrost cycles. It emulates the web fingerprints of two real refrigeration controllers, the Danfoss AK-SM 800A and Dixell XWEB EVO, so attackers think they've hit real hardware, while every action is only logged, never executed. Ideal for DevOps, self-hosted security researchers, and engineers wanting to observe ICS scanning behavior. - **Recent buzz**: 289 points, 70 comments on Hacker News (observed 2026-11-13 at publication), 73 GitHub stars, MIT license. - **Key features**: Exact replication of HTTP header ordering, TLS 1.2 certificate (CN=DanfossSM800A), favicon hash, Angular landing page Last-Modified/ETag; built-in detection for 8 CVEs/public exploits (including CVE-2025-41450 code-of-the-day bypass, CVE-2026-25085 XWEB Pro auth_mode bypass); post-login returns a fake dashboard with a defrost button, all operations logged as JSONL; provides `summary.py` 24-hour auto-summary reports. - **Quick start**: Local test `PERSONA=danfoss HTTP_PORT=8080 python3 -I honeypot.py` spins up on port 8080; production deploy by pasting `cloud-init.yaml` into an Ubuntu 24.04 VPS user data, two minutes to live (a $4 Droplet suffices), just remember to only expose the honeypot port and your own SSH IP. - **vs. alternatives**: More focused on web fingerprint accuracy and specific vulnerability detection than `eppser/danfoss-ak-sm-decoy`, and adds the Dixell XWEB persona; lighter than the general-purpose industrial honeypot Conpot, optimized for cold-chain attack surface. - **Who it's for**: Security engineers wanting low-cost, high-interaction ICS honeypots to observe real-world scanning and exploitation behavior. - **Link**: [hedgerow-dev/coldframe](https://github.com/hedgerow-dev/coldframe) ### 2. LearnHarness: Knowledge-Graph Desktop App That Helps Engineers Actually Learn New Tech - **What it is**: An AI learning companion desktop app built for engineers (macOS/Windows/Linux). Uses a four-stage flow, "measure existing understanding → plan dependency graph → Socratic step-by-step teaching → varied practice", with a persistent knowledge graph tracking propositions and reasoning chains. Solves the real pain point of "reading docs but not grasping core concepts." AGPL-3.0 open source, supports local models, no subscription lock-in. - **Recent buzz**: 9,210 GitHub stars (new project within 30 days, observed 2026-11-13 at publication), primary language TypeScript. - **Key features**: Teaching phase enforces "predict → explain → confirm" three-step loop, forcing you to think out loud instead of passively receiving answers; practice questions auto-generated from the knowledge graph, requiring active recall instead of recognition; desktop-native drag-and-drop PDFs/images, voice input, web search (Tavily/Brave/Exa/Firecrawl/Ollama), visual explanations and interactive demos; all data stays local, system prompts viewable and editable. - **Quick start**: Download the platform installer from [learnharness.ai](https://learnharness.ai) (macOS signed DMG, Windows installer, Linux AppImage/.deb), launch, configure API key or local model endpoint (Ollama, OpenAI-compatible endpoints both work), start your first lesson. - **vs. alternatives**: Unlike ChatGPT/Claude which just give answers, or generic RAG tools, LearnHarness forces "thinking out loud" and builds a personalized knowledge graph, closer to an Anki + tutor hybrid; AGPL-3.0 license means commercial internal deployments need compliance review. - **Who it's for**: Engineers who want deep understanding of new architectures, languages, or paper core concepts, not satisfied with shallow Q&A. - **Link**: [amosblomqvist/learnharness](https://github.com/amosblomqvist/learnharness) ## Closing Two tools today, one defense, one offense. Coldframe exposes the ICS attack surface in the lightest way possible; LearnHarness internalizes knowledge in the most thorough way. If you have a cloud box and want to watch real scanning behavior, Coldframe can be running tonight. If you need to chew through a gnarly tech stack, LearnHarness is worth downloading for one lesson. See you tomorrow, keep digging for the good stuff. --- ## About this article and its author Originally published on [Mark Ku's Tech Notes](https://blog.markkulab.net/en/open-source-weekly/open-source-weekly-2026-11-08) License: [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/) — when reusing or quoting, credit the author and link back to the original ### About the author **[Mark Ku](https://blog.markkulab.net/en/author/mark-ku)** — Software engineer - 10+ years as a software engineer - Built North-American e-commerce and AI SaaS subscription billing ### Free tools built by the author All of these are free to use: - [Free PDF Sign Tool](https://blog.markkulab.net/en/tools/pdf-sign): Online PDF sign tool — draw, type, or upload a signature, then drag, resize, and download. Everything runs in your browser; nothing is uploaded. - [VS Code Refactory](https://blog.markkulab.net/en/tools/refactory): Refactory is a VS Code refactoring extension: 34 actions plus a 37-rule code-smell inspection layer with a Code Health dashboard, across 18 languages, backed by 534 tests. It learns your repo's conventions: where interfaces live, where DI is registered, whether 'use client' belongs. It ranks files by git churn × complexity so you know what to fix first, and hands any smell to the Claude Code already on your machine. Free to use, and your source never leaves your computer. - [DB-Kit Database Manager](https://blog.markkulab.net/en/tools/db-kit): DB-Kit is a lightweight, cross-platform database manager built with Tauri + Rust + React. Manage MySQL, MariaDB, PostgreSQL, SQL Server, Oracle, SQLite, MongoDB, Redis, Kafka, Elasticsearch and RabbitMQ from one consistent interface: passwords encrypted in the OS keychain, SSH tunnels, full CRUD, a visual query builder, stacked multi-statement result sets, cross-connection data transfer, schema & data compare with sync SQL and schema snapshots, Excel / CSV import & export, visualized execution plans, ER diagrams, scheduled backups, SQL stress testing with p50–p99 latency percentiles, a 15-rule SQL review engine, Review & Run (AI review plus per-statement backups and an auto-generated rollback script), Kafka message browsing with monitoring & alerts, an SSH terminal with SFTP / FTP, Docker / Kubernetes, remote desktop (RDP / VNC / RustDesk), file / folder compare, stored procedure integration tests, six UI languages, a built-in AI assistant (a local CLI or any Anthropic / OpenAI-compatible API; natural-language SQL, AI review and tuning advice) and the dbk CLI. Free and open source (MIT), with installers for Windows, macOS and Linux. - [VS Code Super Mermaid](https://blog.markkulab.net/en/tools/super-mermaid): Super Mermaid is a VS Code extension for beautiful Mermaid diagrams out of the box: auto-colored live preview, mouse pan & zoom, high-res PNG / SVG export, 21 templates and multiple themes. Free and open source (MIT). - [React Super Mermaid](https://blog.markkulab.net/en/tools/react-super-mermaid): react-super-mermaid is an open-source React component library: render beautiful Mermaid diagrams with a single , with built-in colorful / sketch themes, pan & zoom, in-diagram search, and high-res SVG / PNG export. Lightweight, SSR-safe, fully typed. Free and open source (MIT). - [Jira / Confluence Super Mermaid](https://blog.markkulab.net/en/tools/jira-super-mermaid): An Atlassian Forge app: write Mermaid syntax directly inside a Jira issue or a Confluence page and get flowcharts, sequence diagrams, state machines and Gantt charts. 11 diagram types, SVG / PNG export, light and dark themes, full CJK support. Runs on Atlassian: your diagrams live in your own site and the app calls no third-party service. Free, coming soon to the Atlassian Marketplace. - [Mermaid Live Preview](https://blog.markkulab.net/en/tools/mermaid-preview): Write Mermaid in your browser, see it render instantly, and share the whole diagram as a single link. No sign-up, nothing uploaded to a server, and mermaid.live share links work as-is. - [React Intl Phone Number](https://blog.markkulab.net/en/tools/react-intl-phone-number): react-intl-phone-number is an open-source React component: framework-agnostic and antd-free, with E.164 in/out, a searchable flag / country-code dropdown, configurable validation levels (strict / mobile-strict / loose), themeable CSS, and i18n — phone logic powered by google-libphonenumber. Lightweight and fully typed. Free and open source (MIT). - [Uptime Kuma Cluster](https://blog.markkulab.net/en/tools/uptime-kuma-cluster): Turn single-node Uptime Kuma into a highly available cluster: OpenResty + Lua smart load balancing, shared MariaDB state, health checks and automatic failover, plus cluster-management REST APIs. One Docker Compose command to start. Free and open source (MIT). - [AI Podcast Cut](https://blog.markkulab.net/en/tools/ai-podcast-cut): Drop in a recording and it removes fillers and stutters, levels loudness segment by segment, and sends a second agent to review every cut. Cut points snap to word boundaries and zero crossings, every splice gets a fade, and sentence-end breaths are preserved. Desktop app for Windows, macOS and Linux. MIT licensed; the Windows installer bundles ffmpeg. - [AI Video Cut](https://blog.markkulab.net/en/tools/ai-video-cut): Pick something in your video: type it (face, license plate, phone screen, logo), click points or drag a box, or let Claude Code / Codex pick it. AI Video Cut tracks it frame by frame, then mosaics or blurs it, recolors it, pins stickers and text to it, swaps a screen or poster for your own image or video, or removes it using background that other frames actually captured. Plus sequence editing, local captions and an AI assistant. Free, open-source (MIT) Windows desktop app (macOS / Linux experimental) that runs locally, nothing uploaded. - [open-pos restaurant POS](https://blog.markkulab.net/en/tools/open-pos): One computer and one receipt printer is enough to open the shop. Your data lives on your own disk, no subscription, no lock-in, MIT licensed. Money is integer New Taiwan dollars with tax split by the statutory formula, so sales + tax always equals the total. Printing goes straight over ESC/POS on TCP 9100, with no vendor driver. Tauri + Rust + SQLite desktop app, v1.0 in development. - [.NET e-commerce API template](https://blog.markkulab.net/en/tools/dotnet-ecommerce-api): An e-commerce backend API template built on .NET 10: Controller → Service → Repository layering, Autofac convention-based registration, SqlSugar for MySQL / MariaDB and SQL Server, Redis cache and message queue, Hangfire jobs, JWT auth, and an extensible payment provider module (ECPay, Newebpay). Apache 2.0. - [Open Token Monitor team AI usage](https://blog.markkulab.net/en/tools/open-token-monitor): Collect token usage and equivalent cost from every employee's AI coding tools into a hub you host yourself: PostgreSQL, org roster, dashboards compared by company and department, and a reports API. Electron and Rust/Tauri clients upload every 30 minutes. MIT licensed, one Docker command. - [ai-security-monitor defensive security](https://blog.markkulab.net/en/tools/ai-security-monitor): Your website is live. Who checks its certificates, security settings and known vulnerabilities? A self-hosted Security Hub brings website scans and host monitoring together, deduplicates findings and compares scans after fixes. ### Daily podcasts - [Mark's Tech Insights — Daily AI News](https://blog.markkulab.net/en/category/tech-news): Daily curated AI and tech trends. Catch the latest developments via audio summaries — covering AI applications, software architecture, DevOps, and engineering practice. — RSS: https://blog.markkulab.net/feed.xml - [AI股市蝦聊](https://blog.markkulab.net/en/category/ai-stock-chat): Every trading day, an AI-analyzed take on the Taiwan stock market, delivered as a two-host conversation covering the session and the next-day outlook. — RSS: https://blog.markkulab.net/ai-stock-chat/feed.xml - [開源好物日報](https://blog.markkulab.net/en/category/open-source-weekly): A daily two-host pick of free open-source tools surfaced from real Hacker News, GitHub, and Reddit buzz — what pain they solve and the fastest way to get started. — RSS: https://blog.markkulab.net/open-source-weekly/feed.xml - [AI 運動日報](https://blog.markkulab.net/en/category/sports-weekly): Two hosts talk NBA, MLB and world sport every day — scores, records and the stories behind them, from a Taiwanese fan perspective. — RSS: https://blog.markkulab.net/sports-weekly/feed.xml - [AI 國際新聞快報](https://blog.markkulab.net/en/category/world-news): A daily two-host briefing that makes sense of the past 24 hours in world news — geopolitics, the global economy, conflict and security, disasters and climate — from a Taiwanese perspective, neutral and fully sourced. — RSS: https://blog.markkulab.net/world-news/feed.xml - [地端 AI 實驗室](https://blog.markkulab.net/en/category/local-ai-lab): Every day, a two-host look at open-weight models and LoRAs you can actually run on your own machine: what they are for, whether your GPU can handle them, and how they compare — sourced from official model cards. — RSS: https://blog.markkulab.net/local-ai-lab/feed.xml - [AI 行銷日報](https://blog.markkulab.net/en/category/ai-marketing): Every day, two hosts break down the latest in AI for marketing, advertising, SEO/GEO and content marketing: practical, never sponsored, every story sourced. — RSS: https://blog.markkulab.net/ai-marketing/feed.xml - [AI 資安日報](https://blog.markkulab.net/en/category/ai-security): Every day, two hosts cover the latest where AI meets cybersecurity: LLM and AI agent vulnerabilities, prompt injection, model supply-chain risks and AI-powered attacks, from a defense-first angle with every story sourced. — RSS: https://blog.markkulab.net/ai-security/feed.xml ### Newsletter [Subscribe to the newsletter](https://blog.markkulab.net/en/subscribe) — Be the first to know about new posts. 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