CheckHacks

❓ What is it?

CheckHacks is an innovative server-side anticheat plugin that detects client-side mods and hack clients using the Sign Translation Vulnerability (MC-265322), the same technique used by DonutSMP to catch cheaters on their server. No client-side mod is required, and the entire check happens invisibly: the target player never sees a sign appear or disappear. When a check is triggered, the plugin silently places one or more signs near the player, writes special translation keys on them, forces the client to open and close the sign editor, and reads back the resolved text. Since mods register their own translation keys, a vanilla client and a modded client will always return different responses, revealing exactly which mods are installed.

🧱 Features

• Uses the Sign Translation Vulnerability (MC-265322), works entirely server-side, no client mod needed
• Checks up to 3 mods per sign, multiple signs sent sequentially with configurable delay
• Three detection modes - METEOR, TRANSLATE, KEYBIND, each mod uses the correct one automatically
• Players with exploit protection are marked as PROTECTED instead of false negatives
• Players who don't respond are marked as PROTECTED (likely blocking packets)
• Easily add custom mods to detect by adding entries in config.yml
• /checkhacks <player> - check all configured mods
• /checkhacks <player> meteor-client,freecam - check only specific mods
• /chreload - reload the config without restarting the server
• /chalerts (aliases: /checkalerts, /alerts) - toggle hack detection alerts on/off per player
• /checklang <player> - detect the language of a player's Minecraft client using signs
• /checklang <player> en_us,it_it - check against specific languages only
• Full tab completion on player names, mod IDs and language codes, including comma-separated lists
• Auto-check on player join with configurable delay and optional first-join-only mode
• Auto language check on player join with its own configurable first-join-only mode
• Anticheat integration: triggers automatic checks when Grim, Vulcan or Spartan flags a player
• Configurable cooldown between automatic checks per player to avoid spam
• Separate hack lists for default checks, join checks and anticheat-triggered checks
• Bedrock player detection: players whose name starts with a configured prefix (e.g. . or *) are automatically skipped and flagged as Bedrock
• Results broadcast to all players with the checkhacks.alerts permission
• Players can individually toggle alerts on or off with /chalerts
• Results also sent privately to the player who ran the check if they don't have the alerts permission
• Each result line shows the mod name and its individual outcome: DETECTED, NOT_DETECTED, PROTECTED, SKIPPED
• Shows checker name and reason (manual check, join check, anticheat flag) in every result
• Discord webhook for hack detection results with fully customizable embed message
• Separate Discord webhook for language check results
• Webhook placeholders: &name&, &checker&, &reason&, &hacks&, &results&, &lang&
• Configurable embed color per webhook
• Optional auto-command on positive detection (e.g. tempban %player% 14d Cheating)
• Signs placed and restored invisibly, the target player never sees a permanent sign
• Barrier placed automatically below the sign if needed to keep it supported
• Every message fully editable in config.yml with MiniMessage formatting
• Configurable plugin prefix
• PlaceholderAPI support
• Permissions: checkhacks.check, checkhacks.reload, checkhacks.alerts, checkhacks.checklang, checkhacks.*

🔍 Detected Mods

⚠️ Warning

Mod developers can patch their mods at any time to block or spoof the Sign Translation Vulnerability, potentially making detection unreliable for specific clients. I will do my best to stay ahead of any patches, find bypasses, and continuously add support for new mods of all kinds. This is an ongoing effort, not a one-time solution.

If you need a specific mod added, or have any doubts about how detection works, feel free to DM me on Discord at @branduzzo.

📜 Credits

• Branduzzo - Plugin creator and developer