# How detection via WebRTC works

* The site sends a regular TCP request from the browser (or anti-detect browser).
* The anti-fraud system responds and injects a script for a STUN request.
* The browser makes a STUN request over UDP, bypassing the proxy from the real address, since we remember that a proxy or anti-detect browser may not support UDP.
* If the IPs of the TCP connection and the UDP differ, the user is exposed for using a proxy.<br>

  <figure><img src="https://3044836706-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F3l0uO4OV4DD1gK4uKGC6%2Fuploads%2FhRdCpCRTN1iKVtgwjVhs%2Fimage.png?alt=media&#x26;token=21237d69-2d9d-4a60-8321-25e6e56b3b0c" alt=""><figcaption><p>Image and information kindly taken from the article<a href="https://telegra.ph/Zachem-nuzhny-proksi-s-UDP-i-pri-chyom-tut-protechka-WrbRTC-v-Antike-12-19"> ZloyTeam</a></p></figcaption></figure>
