title: How does reCAPTCHA 3 know I'm using Selenium/chromedriver?
body: <p>I'm curious how reCAPTCHA v3 works. Specifically the browser fingerprinting.</p>
  <p>When I launch an instance of Chrome through Selenium/chromedriver and test against reCAPTCHA 3 (<a href="https://recaptcha-demo.appspot.com/recaptcha-v3-request-scores.php" rel="noreferrer">https://recaptcha-demo.appspot.com/recaptcha-v3-request-scores.php</a>) I always get a score of 0.1 when using Selenium/chromedriver.</p>
  <p>When using incognito with a normal instance, I get 0.3.</p>
  <p>I've beaten other detection systems by injecting JavaScript and modifying the web driver object and recompiling webdriver from source and modifying the <code>$cdc_</code> variables.</p>
  <p>I can see what looks like some obfuscated <a href="https://en.wikipedia.org/wiki/POST_%28HTTP%29" rel="noreferrer">POST</a> back to the server, so I'm going to start digging there.</p>
  <p>What might it be looking for to determine if I'm running Selenium/chromedriver?</p>