Undetectable by Design: The Code Behind the Cheaters
Undetectable by Design: The Code Behind the Cheaters
Online chess has experienced unprecedented growth in recent years, largely due to platforms like Chess.com, where millions of players compete daily. However, this growth has been accompanied by a disturbing rise in cheating. In March 2025 alone, Chess.com reported the banning of over 106,000 accounts for violations of its fair-play policies—a staggering figure that illustrates the scale of the problem threatening the integrity of the game.
When we think of cheating in chess, the traditional image involves a player consulting a chess engine like Stockfish on another device. Yet, the reality today is far more complex. Cheaters now leverage browser extensions, custom scripts, hidden mobile apps, and remote-controlled systems, all designed to avoid detection.
This article explores the modern landscape of online chess cheating—how it works, how it’s evolving, and why it’s harder than ever to detect. It is no longer a question of simply using an engine, but of how covertly and effectively that assistance is integrated into the gameplay.
1. Modern Cheating Tools: Beyond the Chess Engine
Some tools are disguised as educational browser extensions, but upon inspection, they reveal an arsenal of features crafted to assist in live games:
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Real-time position analysis:
The software continuously evaluates the board after each move, displaying evaluation bars and move quality. -
Move suggestions:
Subtle visual cues are embedded directly in the interface to advise the cheater on the best moves. -
Automatic execution of engine-recommended moves:
Functions simulate mouse events to execute moves, closely mimicking human interaction. -
This persistent channel ensures that data, such as the scrapped game state, is transmitted reliably—even if the connection is temporarily lost.
Input Simulation and Auto-Move Execution
To simulate human input, the scripts include functions that mimic mouse events on the game board. For example:
Locally embedded engines:
A complete version of Stockfish can be embedded using WebAssembly, eliminating the need for external engines and reducing latency.
While these features may have educational merit in post-game analysis, their use during live games constitutes clear violations of fair-play policies and provides an unfair advantage.
2. Streamable and "Undetectable": The Rise of Covert Cheating Systems
An even more troubling trend is the emergence of tools marketed as "undetectable." These systems go beyond mere suggestions—they are designed for stealth, automation, and even compatibility with live broadcasts:
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Auto-play functionality:
Moves can be executed without user interaction. -
Smart premove systems:
The software anticipates the next best move and plays it instantly. -
Forced-mate recognition:
Winning combinations are detected and executed automatically. -
"Stream-safe" interfaces:
The cheating overlay is hidden during screen sharing or live streaming so that observers see only a benign interface.
These tools are sold privately, often with active support, constant updates, and forums where users share configurations to minimize detection risk. This is no longer simple cheating—it is a full-fledged ecosystem of commercialized deception.
3. Technical Dissection: Local Engine Integration and Interface Manipulation
Our reverse engineering process revealed two distinct approaches among these tools. Below, we present only the most relevant parts of the code that illustrate their core functionalities.
Code Injection via Manifest
The extension injects its code into chess platforms using Chrome’s content scripts. For example, the manifest file includes:
This simple injection mechanism allows the cheat to monitor gameplay in real time and interact directly with the game interface.
Embedded Stockfish Engine
One solution embeds Stockfish directly into the browser with WebAssembly. This ensures that high-speed evaluations occur locally, with minimal latency:
By embedding Stockfish this way, the tool eliminates the need for external resources, enhancing both performance and stealth.
Input Simulation and Auto-Move Execution
To simulate human input, the scripts include functions that mimic mouse events on the game board. For example:
This technique allows the cheat to execute moves automatically, replicating the nuances of human interaction.
Console Hijacking and Obfuscation
To avoid detection, the cheat overwrites browser logging functions and obfuscates variable names:
This simple yet effective approach prevents developers and anti-cheat tools from easily tracing the extension’s activities.
Hidden User Interface
The extension’s settings interface is kept hidden from the main site, loaded via a separate HTML popup. This UI lets users configure parameters such as engine depth, automation toggles, and move delays—all without drawing unwanted attention.
Advanced Architecture: Covert WebSocket Communication and Remote Control
A second, more advanced tool operates differently. Instead of embedding a local engine, it uses a remote-controlled architecture. The software continuously exfiltrates game data and transmits it to a third-party server.
Encrypted Server Endpoint
The cheat encrypts its WebSocket endpoint using a basic XOR cipher, decoded only at runtime:
This obfuscation helps the tool avoid detection by basic browser inspection tools.
Persistent WebSocket Communication
The WebSocket client is designed to maintain a constant, self-healing connection:
This persistent channel ensures that data, such as the scrapped game state, is transmitted reliably—even if the connection is temporarily lost.
Deceptive Appearance
The extension’s interface is intentionally kept blank and disguised as a productivity tool (e.g., "Easy Snap Version"). Misleading descriptions and harmless CSS overlays further disguise its true intent during screen sharing or live broadcasts.
A Call to Action for Chess.com: Specific Detection Recommendations
Based on our analysis of modern chess-cheating systems, we propose the following targeted strategies to enhance detection:
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Monitor for Unusual DOM Mutation Patterns:
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Heuristic Triggers: Implement detection rules that flag scripts using rapid, repetitive MutationObservers combined with debouncing logic in multiple pages.
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Alert on Element Sanitization: Compare the expected structure of the chessboard DOM with unusually “cleaned” outputs; such significant filtration may indicate attempted exfiltration of board state.
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Detect Obfuscated WebSocket Endpoints:
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Network Anomaly Detection: Deploy monitoring that examines the byte patterns or unexpected renegotiation behavior in WebSocket connections. For instance, flag connections whose endpoints are resolved by simple XOR decryption routines instead of standard URLs.
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Behavioral Baseline: Establish a baseline of normal WebSocket communications from trusted sources, and generate alerts when connections exhibit non-standard or persistently self-healing reconnection attempts.
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Identify Synthetic Input Simulation:
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Mouse Event Timing Analysis: Analyze the timing and distribution of mouse events (e.g., rapid, perfectly timed clicks) in live games. Comparing these with historical data of natural human input can reveal automation.
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Debug Command Surveillance: Monitor for the use of browser debugging APIs (e.g., chrome.debugger.sendCommand) particularly on the chessboard elements. Unexpected use of such commands could indicate simulation of user input.
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Flag Unusual Console Behavior and Global Variable Overwriting:
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Integrity Checks: Regularly verify the integrity of native console functions. Any unexpected modifications (e.g., logging functions overridden to empty functions) should trigger a review.
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Global Scope Audits: Analyze the browser’s global namespace for anomalous variables introduced by extensions. Variables or objects that hide under seemingly generic names (like "master" or "ecoTable") may be a sign of covert cheat tools.
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Examine Hidden Interface Elements:
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CSS and DOM Inconsistencies: Scrutinize pages for hidden popups or “empty” interfaces that should not be present in a standard game environment. Detection systems can flag pages embedding external assets such as “edn.html” through suspicious web-accessible resource configurations.
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Integrate Multi-Factor Correlation:
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Combined Heuristics: Rather than treating these indicators in isolation, use a combined score of identified anomalies (e.g., DOM changes, WebSocket behavior, input simulation patterns) to trigger targeted interventions.
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Historical Trend Analysis: Leverage machine learning or statistical models trained on extensive game session data to dynamically adapt thresholds for each of these indicators.
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4. Internal Communications: Fakes & Fringes of the Underground
In our investigation, we also uncovered snippets of internal chatter among individuals involved in these cheating ecosystems. Although these communications are from anonymous online forums and private chat groups—and have been heavily obfuscated—they offer a rare glimpse into the underground world of chess cheats:
Developer Chat Excerpt:
"
We are not detected, people have been getting banned for the following.
- Gaining too much elo in a short time. (Hour, day, month.)
- Inconsistent gameplay. (Makes it easy for Fairplay Team to notice you are cheating.)
- When you are autoplaying, move times must be for the mode you are playing. (Example: having 1.2 sec, 0.5 sec, move times in a mode such as blitz or rapid when it only works in bullet/ultra bullet.
- Not having variation when it comes to auto play. (You need to change your move time config slightly as you play or as games so on.)
- Not being aware how blatant you are playing, it becomes very clear after a few moves sometimes, learn chess, don't just cheat without knowing chess.
- If you were previously banned, you might not have changed your fingerprint/data the site see's enough and they linked you to another account or to a past cheater.
- Using a stolen account and not playing as the person played beforehand.
- Playing way too well for your elo.
"
Cheater Forum Message:
"full fledged and a complete chess External GUI to shit on the face of any anticheat XD , stream with open heart and destroy IM/CM/GM or anybody flex your puzzle skills too code will remain private but the exe will be released next week "
Some of them even share their public Chess.com profiles where they actively cheat. For obvious reasons, I won’t include them here
Media Leak :
They are so proud that they even have forums where they post whether they win or 'humiliate titled players or celebrities', and even a website where you can see the number of people in real-time using their chess cheats.
Thank you for joining me on this deep dive into the hidden mechanics of modern chess cheating. As the tactics evolve and technology advances, staying informed becomes crucial to preserving the integrity of the game. We hope this exploration has shed light on the complexities and challenges faced by platforms and players alike.
Keep questioning, keep learning, and together, let’s work toward a fair and transparent future for online chess.
Happy playing and stay vigilant!
Edit: Comments have been restricted due to the sharing of cheating-related information and public accusations.
