Team beta version

Note: This plugin requires HTTPS to function (due to Web Crypto API usage).
The Story: The Forging of the Ultimate Defense
This project began with a simple goal: to create a lightweight honeypot trap to catch basic bots. But during development, we faced a harsh reality: Simple traps are obsolete. Modern AI bots and headless browsers can easily step over traditional defenses. A basic trap was no longer enough; we needed a fortress.
So, we forged a completely new architecture. We added Proof of Work, Behavioral Analysis, and Rate Limiting. What started as a simple honeypot evolved into a 15-layer invisible firewall. Like a samurai’s blade, it operates with absolute precision—completely invisible to your real customers, yet ruthlessly executing a “Silent Kill” on spam bots before they ever reach your inbox or database.
Samurai Honeypot protects every Contact Form 7 and WPForms form with fifteen independent defense layers. 
Each layer contributes a score, and blocked submissions are handled by a 3-Tier Triage System:
<h4>3-Tier Triage System</h4>
<ul>
<li>Tier 1 (Pass): Score below the threshold (default 50) — email is sent normally.</li>
<li>Tier 2 (Quarantine): Score between the threshold and 99 — email is silently suppressed (Silent Kill) and the submission is saved to the built-in Quarantine Log for admin review.</li>
<li>Tier 3 (Drop / Instant Kill): Score of 100 or higher — email is silently suppressed and the submission is permanently dropped without logging. This protects your database from bloat during DDoS or mass bot attacks.</li>
</ul>
Warning — False Positives: Depending on your environment, legitimate emails may occasionally be flagged as spam. Enterprise proxies, strict corporate firewalls, outdated browsers, VPNs, and unusual network configurations can trigger detection layers. You MUST check the Quarantine Log periodically to identify and recover any false positives. The plugin cannot distinguish all edge cases automatically.
<h4>Defense Layers</h4>
<ol>
<li>JS Injection Gate — Blocks bots that cannot execute JavaScript. Tokens are fetched via REST API for full page-cache compatibility.</li>
<li>Polymorphic Honeypot — Decoy field name is cryptographically derived per token (not exposed in the API response), hidden from humans via CSS.</li>
<li>Token Signature — HMAC-SHA256 signed stateless token with IP and Form ID binding.</li>
<li>Time Trap — Detects impossibly fast submissions. Browser autofill is automatically exempt.</li>
<li>Proof of Work — SHA-256 computational challenge via Web Crypto API that forces CPU cost on bots.</li>
<li>Behavioral Entropy — Hash-verified human-like event counters: mouse, keyboard, touch, scroll. Uniqueness tracking detects script reuse.</li>
<li>Headless UA Block — Server-side User-Agent check instantly blocks known headless browsers and automated tools (Headless Chrome, Puppeteer, PhantomJS, Selenium, Playwright, Nightmare, Electron). Toggleable in settings for E2E testing compatibility.</li>
<li>Headless Detection — Detects automated browser environments (navigator.webdriver, plugin count, window.chrome, language count).</li>
<li>UA Age Detection — Scores based on Chrome version age. 2+ years: +10, 3+ years: +20, 4+ years: +30. Bots often use hardcoded old User-Agent strings that never update.</li>
<li>Rate Limiting — Per-IP submission rate limiting with IPv6 /64 normalization.</li>
<li>Replay Protection — Atomic token consumption (INSERT IGNORE) + TTL expiry enforcement.</li>
<li>IP Blacklist — Manually configured IP/CIDR blacklist for known bad actors.</li>
<li>Content: URL Limit — Flags messages containing more URLs than the configured threshold.</li>
<li>Content: BBCode — Detects BBCode link syntax (<code>[url=...]</code>) that never appears in legitimate form submissions.</li>
<li>Content: Denylist — Matches against WordPress Disallowed Comment Keys (Settings > Discussion).</li>
</ol>
<h4>Key Features</h4>
<ul>
<li>3-Tier Triage — Pass, Quarantine (with local log), or Drop. No legitimate message is lost without a trace — quarantined submissions are saved for admin review.</li>
<li>Built-in Quarantine Log — Blocked Tier 2 submissions are saved to a local database table (up to 1,000 entries, FIFO). View date, score, trigger reasons, and full form data from the admin panel. No external plugin required.</li>
<li>DDoS-Resilient Tier 3 Drop — Submissions scoring 100+ are immediately dropped from memory without any database write. This prevents database exhaustion during mass bot attacks.</li>
<li>GDPR Compliant — No cookies, no external service calls, no plugin-specific PII stored. IP addresses are one-way hashed with a site-specific salt before any storage — raw IPs never touch the database. No consent banner required.</li>
<li>Stateless Tokens — No database writes for token generation; prevents DoS via DB bloat.</li>
<li>Zero Trust Client — All client-submitted data is verified server-side with HMAC signatures and hash integrity checks.</li>
<li>Zero Configuration — Activate and all Contact Form 7 / WPForms forms are protected automatically.</li>
<li>Cache Compatible — Tokens are fetched via REST API, so page caching works fine.</li>
<li>Multiple Forms — Works correctly with multiple forms on the same page.</li>
<li>IP Whitelist / Blacklist — Whitelist trusted IPs or CIDR ranges to skip all scoring. Blacklist known bad IPs to add +100 score instantly. Optionally whitelist all logged-in WordPress users.</li>
<li>Headless Browser Blocking — Server-side User-Agent check instantly blocks Headless Chrome, Puppeteer, Selenium, and other automated browsers (+100 score). Enabled by default; can be toggled off for E2E testing.</li>
<li>Content Rules — Detect spam patterns in form content: excessive URLs, BBCode link syntax, and WordPress Disallowed Comment Keys matching.</li>
<li>Trusted Proxy Support — Optional mode for Cloudflare and reverse proxy environments with IP range validation.</li>
<li>Lightweight — Three PHP files, no external dependencies, no jQuery.</li>
</ul>

Samurai Honeypot for Forms

Invisible 15-layer anti-spam for Contact Form 7 & WPForms. Score-based 3-Tier Triage silently blocks bots — no CAPTCHA, no user friction.

Jeff Starr

<blockquote>
✨ Trap bad bots in a virtual black hole
</blockquote>
Important: Do NOT use this plugin on sites with caching. <a href="https://wordpress.org/support/topic/important-do-not-use-on-sites-with-caching/" rel="ugc">Learn more »</a>
👾 Bye bye bad bots..
Bad bots are the worst. They do all sorts of nasty stuff and waste server resources. The Blackhole plugin helps to stop bad bots and save precious resources for legit visitors.
👾 How does it work?
First the plugin adds a hidden trigger link to the footer of your pages. You then add a line to your robots.txt file that forbids all bots from following the hidden link. Bots that then ignore or disobey your robots rules will crawl the link and fall into the trap. Once trapped, bad bots are denied further access to your WordPress site.
I call it the “one-strike” rule: bots have one chance to obey your site’s robots.txt rule. Failure to comply results in immediate banishment. The best part is that the Blackhole only affects bad bots: human users never see the hidden link, and good bots obey the robots rules in the first place. Win-win! 🙂
<blockquote>
✨ Add a blackhole trap to help stop bad bots
</blockquote>
Important: Do NOT use this plugin on sites with caching. <a href="https://wordpress.org/support/topic/important-do-not-use-on-sites-with-caching/" rel="ugc">Learn more »</a>
👾 Features
<ul>
<li>Easy to set up</li>
<li>Squeaky clean code</li>
<li>Focused and modular</li>
<li>Lightweight, fast and flexible</li>
<li>Built with the WordPress API</li>
<li>Works with other security plugins</li>
<li>Easy to reset the list of bad bots</li>
<li>Easy to delete any bot from the list</li>
<li>Regularly updated and “future proof”</li>
<li>Blackhole link includes “nofollow” attribute</li>
<li>Plugin options configurable via settings screen</li>
<li>Works silently behind the scenes to protect your site</li>
<li>Whitelists all major search engines to never block</li>
<li>Focused on flexibility, performance, and security</li>
<li>Email alerts with WHOIS lookup for blocked bots</li>
<li>Complete inline documentation via the Help tab</li>
<li>Provides setting to whitelist any IP addresses</li>
<li>Customize the message displayed to bad bots 😉</li>
<li>One-click restore the plugin default options</li>
<li>Does NOT use or require any .htaccess rules</li>
</ul>
Blackhole for Bad Bots protects your site against bad bots, spammers, scrapers, scanners, and other automated threats.
<blockquote>
✨ Not using WordPress? Check out the <a href="https://perishablepress.com/blackhole-bad-bots/" rel="nofollow ugc">standalone PHP version of Blackhole</a>!
</blockquote>
👾 Whitelist
By default, this plugin does NOT block any of the major search engines (user agents):
<ul>
<li>AOL.com</li>
<li>Baidu</li>
<li>Bingbot/MSN</li>
<li>DuckDuckGo</li>
<li>Googlebot</li>
<li>Teoma</li>
<li>Yahoo!</li>
<li>Yandex</li>
</ul>
These search engines (and all of their myriad variations) are whitelisted via user agent. So are a bunch of other “useful” bots. They always are allowed full access to your site, even if they disobey your robots.txt rules. This list can be customized in the plugin settings. For a complete list of whitelisted bots, visit the Help tab in the plugin settings (under “Whitelist Settings”).
<blockquote>
✨ Check out <a href="https://plugin-planet.com/blackhole-pro/" rel="nofollow ugc">Blackhole Pro</a> and level up with advanced features!
</blockquote>
👾 Exclusive Pro Features
<ul>
<li>Option to disable for logged-in users</li>
<li>Threshold control (number of allowed hits)</li>
<li>Custom email alerts</li>
<li>Custom messages for blocked bots</li>
<li>Custom redirect for blocked bots</li>
<li>Custom blackhole trigger links</li>
<li>Complete inline documentation</li>
<li>Block bots based on user agent</li>
<li>Block bots based on IP address</li>
<li>Whitelist/allow bots by user agent</li>
<li>Whitelist/allow bots by IP address</li>
<li>Redirect whitelisted bots</li>
<li>Set custom HTTP Status Code</li>
<li>Full-featured Bad Bot Log with paging, sorting, and field search</li>
<li>Manually add bad bots to the Bad Bot Log</li>
<li>Geo/IP location lookups for each bad bot</li>
<li>Logs number of blocked hits for each bot</li>
</ul>
..plus everything the free version can do and more.
<blockquote>
✨ Learn more and <a href="https://plugin-planet.com/blackhole-pro/" rel="nofollow ugc">get Blackhole Pro »</a>
</blockquote>
👾 Privacy
User Data: This plugin automatically blocks bad bots. When bad bots fall into the trap, their IP address, user agent, and other request data are stored in the WP database. No other user data is collected by this plugin. At any time, the administrator may delete all saved data via the plugin settings.
Services: This plugin does not connect to any third-party locations or services.
Cookies: This plugin does not set any cookies.
Credit: Header Image Courtesy NASA/JPL-Caltech.
Blackhole for Bad Bots is developed and maintained by <a href="https://x.com/perishable" rel="nofollow ugc">Jeff Starr</a>, 15-year <a href="https://plugin-planet.com/" rel="nofollow ugc">WordPress developer</a> and <a href="https://books.perishablepress.com/" rel="nofollow ugc">book author</a>.
👾 Support development
I develop and maintain this free plugin with love for the WordPress community. To show support, you can <a href="https://monzillamedia.com/donate.html" rel="nofollow ugc">make a donation</a> or purchase one of my books:
<ul>
<li><a href="https://wp-tao.com/" rel="nofollow ugc">The Tao of WordPress</a></li>
<li><a href="https://digwp.com/" rel="nofollow ugc">Digging into WordPress</a></li>
<li><a href="https://htaccessbook.com/" rel="nofollow ugc">.htaccess made easy</a></li>
<li><a href="https://wp-tao.com/wordpress-themes-book/" rel="nofollow ugc">WordPress Themes In Depth</a></li>
<li><a href="https://books.perishablepress.com/downloads/wizards-collection-sql-recipes-wordpress/" rel="nofollow ugc">Wizard’s SQL Recipes for WordPress</a></li>
</ul>
And/or purchase one of my premium WordPress plugins:
<ul>
<li><a href="https://plugin-planet.com/bbq-pro/" rel="nofollow ugc">BBQ Pro</a> – Blazing fast WordPress firewall</li>
<li><a href="https://plugin-planet.com/blackhole-pro/" rel="nofollow ugc">Blackhole Pro</a> – Automatically block bad bots</li>
<li><a href="https://plugin-planet.com/banhammer-pro/" rel="nofollow ugc">Banhammer Pro</a> – Monitor traffic and ban the bad guys</li>
<li><a href="https://plugin-planet.com/ga-google-analytics-pro/" rel="nofollow ugc">GA Google Analytics Pro</a> – Connect WordPress to Google Analytics</li>
<li><a href="https://plugin-planet.com/head-meta-pro/" rel="nofollow ugc">Head Meta Pro</a> – Ultimate Meta Tags for WordPress</li>
<li><a href="https://plugin-planet.com/rest-pro-tools/" rel="nofollow ugc">REST Pro Tools</a> – Awesome tools for managing the WP REST API</li>
<li><a href="https://plugin-planet.com/simple-ajax-chat-pro/" rel="nofollow ugc">Simple Ajax Chat Pro</a> – Unlimited chat rooms</li>
<li><a href="https://plugin-planet.com/usp-pro/" rel="nofollow ugc">USP Pro</a> – Unlimited front-end forms</li>
</ul>
Links, tweets and likes also appreciated. Thank you! 🙂

Blackhole for Bad Bots

Отличный инструмент

Simple. I install this every time I spin up a new WordPress site.

Simple

Blackhole is a WordPress security plugin that detects and traps bad bots in a virtual black hole, where they are denied access to your entire site.

Samurai Honeypot for Forms vs Blackhole for Bad Bots