This translation happens through DNS servers. By default your device sends these queries through your Internet Service Providers DNS servers, creating a detailed record of every site you visit tied directly to your actual location and identity.
But when you're running a proxy setup heres the fundamental problem: your proxy might route your regular web traffic, but DNS queries often bypass this tunnel completely. Some browsers especially older versions, might still send DNS queries directly to your ISP's servers even when using HTTPS. The result? Your supposedly secure connection is leaking like a rusty bucket.
This creates a fatal fingerprinting problem. Your traffic appears to come from one location but the initial DNS lookup reveals your true origin. For anti-fraud systems, this inconsistency bumps your fraud score pretty nicely and you transactions get fucked.
How Youre Getting Caught Red-Handed
The thing to remember is that anti-fraud systems aren't just sitting around waiting for you to fuck up—theyre actively hunting for inconsistencies in your setup. These systems deploy sophisticated traps specifically designed to expose you: one of it is DNS leaks.
When you visit a merchant site with anti-fraud protection they inject JavaScript code that forces your browser to request resources from uniquely generated domains they control. Since they own these domains, they control the authoritative DNS servers that answer these queries. When your browser asks "where's uniqueID123.fraudcheck.com?" that question gets logged at their server—complete with which ISP server is making the request and timing information. See this example of it in action with Forter:
If your DNS traffic isnt properly tunneled through your proxy, the query to get the IP of this subdomain comes directly from your own ISP. The anti-fraud system now sees two conflicting stories: your web traffic claims you're browsing from Miami but your DNS resolution originated from an ISP in Moscow. Game over.
Some advanced systems go even further by forcing multiple resolution requests through different methods. They might trigger WebRTC connections that bypass standard proxy settings, or use timing analysis to determine if your DNS requests are taking suspiciously long. By the time you hit "submit" on that order form theyve already flagged your session as suspicious based on these inconsistencies.
Some Solutions
Modern anti-detect browsers typically handle DNS leakseffectively but your setup matters. Whenever possible, use a Socks5 proxy as it inherently routes DNS queries through the proxy itself, significantly reducing the risk of leaks. Ensure your browser is always updated and properly configured to delegate DNS resolution directly to your Socks5 proxy.