Richard Kahn
Residential proxies are one of the most difficult forms of fraudulent traffic to detect, because they are specifically designed to look like ordinary people. The most accurate way to detect a residential proxy is to evaluate the actual visitor at the moment of each connection, rather than relying on whether an IP address appeared on a proxy list at some point in the past. Visitor-level detection avoids the false positives that come from judging an entire IP address based on the behavior of a single device behind it.
This article explains what a residential proxy is, how fraudsters use them, why the most common detection method produces false positives, and what accurate detection actually looks like.
What Is a Residential Proxy?
A residential proxy routes internet traffic through a real, ISP-assigned IP address on a home internet connection that belongs to an everyday consumer device, such as a laptop, desktop, or smart TV. Because the traffic exits through a genuine residential connection, it looks like it is coming from a normal household rather than a data center.
In many cases, the owner of that device does not know their connection is being used this way. Residential proxy access is often bundled into free apps, browser extensions, or “free VPN” services, with the proxy enrollment buried in the terms of service. In other cases, the software is installed through malware without the owner’s knowledge or consent. Once installed, the proxy service can switch the connection on and off and route other people’s traffic through that home IP address.
How Fraudsters Use Residential Proxies
Residential proxies are valuable to fraudsters for one reason: they make automated and malicious activity look like it is coming from a real person in a real home.
Traditional fraud detection often relies on spotting traffic from data centers, hosting providers, and known VPN ranges. Residential proxies bypass that entirely. Because the traffic originates from legitimate consumer ISPs, it blends in with normal user behavior and slips past detection methods that only look for obvious red flags.
This makes residential proxies a common tool in:
- Ad fraud, where bots generate fake clicks and impressions that appear to come from real households, draining advertising budgets and corrupting campaign data.
- Account takeover and credential stuffing, where attackers test stolen credentials while appearing to log in from ordinary residential locations.
- Scraping and inventory abuse, where automated tools harvest data or hoard products while evading rate limits and bot defenses.
- Location spoofing, where fraudsters appear to be in a specific city or country to defeat geo-based rules.
The common thread is disguise. A residential proxy lets fraudulent traffic wear the identity of a real consumer.
Why IP-Based Detection Creates False Positives
The most common way to detect residential proxies is to maintain a list of IP addresses where proxy activity has recently been observed, often within a rolling window that typically ranges from the past 7 to 30 days. If a proxy connection is detected on an IP address, the entire IP is added to the list, and every visitor from that address is treated as a residential proxy until it drops off.
The problem is that an IP address rarely represents a single person or a single device.
Consider the Smith household: two parents and two children, all sharing one home internet connection and one public IP address. Suppose one of the children installs an app that quietly enrolls their device into a residential proxy network while it runs. An IP-list approach detects proxy activity on the household IP and flags it. For the duration of that window, every visitor from that address is labeled a residential proxy.
But when Mr. Smith logs in from his own clean laptop on that same connection, he is not running a proxy at all. His traffic is completely legitimate. Under an IP-list model, he gets flagged anyway, simply because he shares an address with a device that was compromised.
That is a false positive, and it is a direct consequence of judging the IP address instead of the visitor. Because IP addresses are shared and conditions change from one visitor to the next, an IP lookup can never be accurate about any single individual.
The Most Accurate Way to Detect Residential Proxies
Accurate detection comes from evaluating the actual visitor at the moment of each connection, rather than inheriting a verdict from a list.
This is the approach Anura takes. Instead of asking whether an IP address ever showed proxy activity, Anura assesses each individual visitor in real time to determine whether that specific session is being routed through a proxy.
In the Smith example, this distinction matters. Anura would correctly identify the child’s device as proxy traffic while letting Mr. Smith’s clean connection through untouched. Same household, same IP address, two different and correct verdicts, because the two visitors are in fact different.
This visitor-level method is what makes the difference between detection you can act on and detection that quietly blocks your real customers. Marking 100 percent of an IP’s traffic as a residential proxy will inevitably catch legitimate users in the net. Examining each visitor at the point of connection eliminates that collateral damage.
Detection You Can Act On
Residential proxies will continue to evolve, and fraudsters will keep using them precisely because they are hard to spot. The defense is not a longer blocklist. It is a more precise question: not “has this IP ever been a proxy?” but “is this visitor, right now, coming through one?”
Anura is built to that standard. When we mark a visitor as fraud, we want to be right every time, so you can catch the fraud without turning away the customers you worked to earn.
